Visual Studio debugging/loading very slow

Question

I'm at wit's end. Visual Studio is typically painfully slow to debug or just plain load ("start without debugging") my ASP.NET MVC sites. Not always: at first, the projects will load nice and fast, but once they load slow, they'll always load slowly after that. I could be waiting 1-2 minutes or more.

My setup:

I'm using Visual Studio 2012 Express, currently, but I've had the same problem in Visual Studio 2010 Express as well. My solution is stored on a network drive; specifically, it's My Documents redirected to a network drive, if it matters. (It shouldn't. There are times where my site loads very fast under this setup.)

I load in Internet  Explorer 9 usually, but the same problem happens in Firefox.

This can happen in any ASP.NET MVC project I work on, and it seems to revolve around having DisplayTemplates, which all my ASP.NET MVC projects do. And it's all C# and Razor if that mattered.

Symptoms:

The system will load my symbols hundreds of times. Basically, the following, but there are at least 300 such rows, each with ever-so-slightly different DLL files for the same CSHTMLs:

'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_contact.cshtml.22013bb9.xighmhow.dll', Symbols loaded.
'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_contact.cshtml.22013bb9.cv5hktkf.dll', Symbols loaded.
'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_statuscode.cshtml.22013bb9.1o77hs8i.dll', Symbols loaded.
'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_statuscode.cshtml.22013bb9.jja-77mw.dll', Symbols loaded.
'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_location.cshtml.22013bb9.l_e9ev_s.dll', Symbols loaded.
'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_location.cshtml.22013bb9.b4n59gom.dll', Symbols loaded.

In the above, I've got three DisplayTemplates: "Contact", "Location", and "StatusCode". It appears that IIS is loading symbols twice for each time the display template gets called. Thus, if I'm displaying a table of 100 entries that call all three of these display templates, it's 600 separate symbols loaded.

This isn't a fast operation either. The log files that IIS generates take about 200  ms for each symbol to load. Thus, super-long delays.

What I've Tried:

• Debug or Release version, it doesn't matter.
• Putting my project on a full IIS implementation on a web server runs it super fast with no problems.
• Cassini, IIS  Express 7.5, and IIS  Express 8.0 all have the problem.
• Delete All Breakpoints does nothing.
• Clean Solution, or deleting the .suo also do nothing.
• If I repair IIS  Express/ delete the My Docs\IISExpress folder, or repair/reinstall Visual Studio → the issue MAY go away, but only for a while before it comes right back.

Any advice at all is appreciated.

To answer more questions, yes my machine definitely has horsepower. The infuriating thing is that the same project, with NOTHING altered, can sometimes load very quickly, typically after I repair IIS  Express and delete the My Docs\IISExpress folder. Eventually, "something" happens and it's down to 2 minutes to load again. What I'm working on is not a complicated project. No external libraries or dependencies and my VS.NET has no add-ons whatsoever.

Of note, this machine has Symantec Endpoint Protection, which has a history of causing havoc. But disabling it outright (it's good to be an administrator) did not fix the problem.

I have a theory at this point. I'm thinking this is all because I'm working off a redirected folder off a network share. While the debugger was going through its hundreds of "loaded symbols" lines, I paused to see what it was doing. It was in my code, loading the DisplayTemplate I had. Stepping into the template output this:

Step into: Stepping over non-user code 'System.Threading.WaitHandle.InternalWaitOne'
Step into: Stepping over non-user code 'System.Threading.WaitHandle.WaitOne'
Step into: Stepping over non-user code 'System.CodeDom.Compiler.Executor.ExecWaitWithCaptureUnimpersonated'
Step into: Stepping over non-user code 'System.CodeDom.Compiler.Executor.ExecWaitWithCapture'
Step into: Stepping over non-user code 'Microsoft.CSharp.CSharpCodeGenerator.FromFileBatch'
Step into: Stepping over non-user code 'Microsoft.CSharp.CSharpCodeGenerator.System.CodeDom.Compiler.ICodeCompiler.CompileAssemblyFromFileBatch'
Step into: Stepping over non-user code 'System.Web.Compilation.AssemblyBuilder.Compile'
'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_statuscode.cshtml.22013bb9.bciuyg14.dll', Symbols loaded.
Step into: Stepping over non-user code 'System.Web.Compilation.BuildManager.CompileWebFile'
Step into: Stepping over non-user code 'System.Web.Compilation.BuildManager.GetVPathBuildResultInternal'
Step into: Stepping over non-user code 'System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert'
Step into: Stepping over non-user code 'System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory'
Step into: Stepping over non-user code 'System.Web.Mvc.BuildManagerWrapper.System.Web.Mvc.IBuildManager.FileExists'
Step into: Stepping over non-user code 'System.Web.Mvc.VirtualPathProviderViewEngine.GetPathFromGeneralName'
Step into: Stepping over non-user code 'System.Web.Mvc.VirtualPathProviderViewEngine.FindPartialView'
Step into: Stepping over non-user code 'System.Web.Mvc.ViewEngineCollection.Find'
Step into: Stepping over non-user code 'System.Web.Mvc.ViewEngineCollection.FindPartialView'
Step into: Stepping over non-user code 'System.Web.Mvc.Html.TemplateHelpers.ActionCacheViewItem.Execute'
'iisexpress.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\b63f8236\6775085d\App_Web_statuscode.cshtml.22013bb9.kwj3uqan.dll', Symbols loaded.
Step into: Stepping over non-user code 'System.RuntimeType.CreateInstanceSlow'
Step into: Stepping over non-user code 'System.Web.Mvc.DependencyResolver.DefaultDependencyResolver.GetService'
Step into: Stepping over non-user code 'System.Web.Mvc.BuildManagerViewEngine.DefaultViewPageActivator.Create'
Step into: Stepping over non-user code 'System.Web.Mvc.BuildManagerCompiledView.Render'

It looks like Visual Studio is recompiling my display template every time it's called, which is again, hundreds of times. My theory is that Visual Studio compiles the file, saves it to the network share, then somehow stamps a new time on it, and Visual Studio then thinks the file has changed. Thus, Visual Studio recompiles it yet again. Only a theory though; I really have no clue.

For one, apparently, I have offline files (this is a desktop computer in an office; I couldn't care less). I'm going to disable, reboot, and retry tomorrow.

Plus, moving my project, as is, to the local C: fixes it. It loads very quickly. But this is not ideal in a work environment. I lose Previous Versions, my code isn't backed up at all unless I manually copy it, and it's no longer shared with anyone.

I can make do with copying it back and forth from C to the network share if it comes to it. It's much more annoying to wait two minutes for every page to load.

Answer 1

My answer will help to speed up local application Just go to task manager -> details -> Devenv.exe Right cick -> set priority to Realtime.

Plus you can copy the database to local pc which also helps a lot.

Answer 2

I solved the issue by unchecking the following Debug option:

Debug > Options > General > Enable Disgnostic Tools While Debugging

Answer 3

For me simply IIS was not running. Open IIS, spread Sites and "start" the Default Web Site.

Answer 4

to Clear cache etc. use Options 1 & 2; for settings/troubleshooting Options 3 & 4, enjoy!

Option 1: Navigate to IIS express , clear cache and sites

cd "C:\Program Files (x86)\IIS Express\"

• run this appcmd.exe list site /xml | appcmd delete site /in
• run this Del /S /F /Q %temp% - to clear the Userprofile Temp folder.
• run this Del /S /F /Q %Windir%\Temp

Also, clear your temp files in %temp% and logout, or reboot

this clears the Windows temp folder. This will delete all the sites, enjoy!

---

Option 2: remove/recreate the temp folders

• Cmd> rmdir C:\Users\\{username}\AppData\Local\Microsoft\WebsiteCache /s /q
• Cmd> rmdir C:\Users\\{username}\AppData\Local\Temp /s /q

---

Option 3: JMC (Just My Code) Option from MSDN

To enable or disable Just My Code in Visual Studio, under Tools > Options (or Debug > Options) > Debugging > General, select or deselect Enable Just My Code.

---

Option 4: configure the Visual Studio/Disable Common plugin issues

Even more Visual Studio settings You can also configure the Visual Studio and disable resource-killing features on the environment, cant remember where I got this, but threes some more I will post shortly.

Environment -> General

• Uncheck “Automatically adjust visual experience based on client performance”
• Uncheck “Enable rich client visual experience” Check “Use hardware graphics acceleration if available” Environment -> AutoRecover
• Uncheck “Save AutoRecover information every”
• Environment -> Documents
• Check “Save documents as Unicode when data cannot be saved in codepage” Environment -> Keyboard
• Set “ForceGC” to ctrl+num1
• Set “ReSharper_Toggle” to ctrl+num0 (if ReSharper is used)
• Set “ReSharper_EnableDaemon” to ctrl+num8 (if ReSharper is used) Environment -> Startup
• Set “At startup” to “Show empty environment at startup”
• Uncheck “Download content every” Environment -> Synchronized settings
• Uncheck “Synchronize settings across devices when signed into Visual Studio”

Answer 5

For me, I implemented this tip which basically drastically improved performance by adding the following two attributes to compilation tag in web.config

<compilation ... batch="false" optimizeCompilations="true"> ... </compilation>

What does batch="false" do?

It makes pre-compilation more selective by compiling only pages that have changed and require re-compiling

What exactly is the optimizeCompilations doing? Source

ASP.NET uses a per application hash code which includes the state of a number of things, including the bin and App_Code folder, and global.asax. Whenever an ASP.NET app domain starts, it checks if this hash code has changed from what it previously computed. If it has, then the entire codegen folder (where compiled and shadow copied assemblies live) is wiped out.

When this optimization is turned on (via optimizeCompilations="true"), the hash no longer takes into account bin, App_Code and global.asax. As a result, if those change we don't wipe out the codegen folder.

Reference: Compilation element on MSDN

Answer 6

For me it was IE 9.08.8112.16241. As soon as I used Firefox or Chrome there was no sluggish debugging with F10 or F11. I do not know what the problem with IE is but I officially despise using it for testing now.

Update: I have turned off all IE program add-ons and it is back to full speed. Turning them on one at a time revealed that LastPass (in my case) was the culprit. I guess I do not get to blame MS after all.

Several years into the future...
If you are using Brave you can easily access your extensions and turn them off one at a time (or several) while debugging.

brave://extensions

Just click the toggle slider. Notice that all of mine are on except for DuckDuckGo Privacy essentials. They are not removed, just temporarily disabled.

Answer 7

Another last resort solution with respect to time is to repair the VS installation.

• Go to Tools => Get Tools and Features
• Locate the existing VS installation, and choose repair under the more button.
  • For example: Visual Studio Enterprise 2019 installation.

Answer 8

As title says, VS debugging is slow. I can't find my problem, so post it here, may be it helps someone.

In my case slow debugging was on the website hosted in IIS.

• VS 2019 (16.4.4)
• VS 2017 (15.9.19)
• Windows 10 (1909)
• IIS (10.0.18362.1)
• Edge (44.18362.449.0)

At first time after site loading it works fine, but after 1+ minute it become lagging. Requests are pending for 1-2 minutes (F12 network tab) before my breakpoints can handle them. It was in all my active browsers.

Solution: Do not use Edge with IIS while debugging.

To understand where the problem i spent about 4-5 hours. I used Edge + Chrome for my workflow. For now i use only Chrome (with separated user profiles).

Link that helped me: https://answers.microsoft.com/en-us/windows/forum/all/iis-running-very-slowly-after-windows-10-upgrade/dae433ba-4efe-45ab-aa66-824e6fa92b51 "J Marcos" answer.

Answer 9

Deleting .vs folder inside solution folder fixed the slowness for me in VS2019.

Answer 10

Yet another possible cause is pre-compilation of old projects that exist on the file system but have been removed or partially removed from visual studio.

I had a solution that was taking 3.5 minutes to load after a build, I had a look at the timestamps in Temporary ASP.NET Files and saw that the 3 minute delay was on a file in an old project. Had a look in VS & the project was "unavailable". Deleted it from VS, deleted from the file system, and now we're down to a sweet 8 seconds.

Answer 11

I had accidentally selected the option "Show Threads in Source". On unselecting stepping through the code was normal.

Answer 12

In my case the problem was an external running exe file - namely:

WUDFCompanionHost.exe

under the name of

"Windows Driver Foundation - User-mode Driver Companion Framework Host Process".

Process, which has taken a steady 10% of the CPU. Killing it helped directly and withing a second the page has loaded.

Answer 13

In my case,

I realized that remote debugging runs and consumes most of the resources. I did not really need to make the app 64 bit so after forcing it to be 32 Bit, remote debugging did not run and the execution was faster.

Answer 14

My problem was due to the project being built each time I started debugging. All other solutions in this thread helped slightly, but still resulted in me having to wait until project finished building.

My Solution to avoid the build each time you start debugging:

• Go to Solution Explorer - > Right Click Your Solution File - > Click Properties

• In the Property Pages - > On the left, choose Configuration - > and Uncheck Build

• Click OK

• Ensure you have visual studio open as Administrator

• Go to Debug -> Attach to Process

• CLICK checkbox Show processes from all users -> Find and Select process called w3wp.exe -> Click Attach -> when warning comes up, click Attach

Now you can navigate to the page you are wanting to debug in localhost, and if you have break points set in your file, you can immediately begin debugging without having to wait for your project to build!!

Answer 15

Asp.net core debugging was painfully slow because of unknown VS extension had replaced default Just in Time debugger.

I have found such message in the OPTIONS\DEBUGGING\Just-In-Time configuration tab (as warning text). Another debugger has registered itself as the Just-In-Time debugger. To repair, enable Just-In-Time debugging or run Visual Studio repair.

Description: https://msdn.microsoft.com/en-us/library/ssc8234s.aspx?f=255&MSPPError=-2147217396

Returning back the default JIT debugger (just checked Managed option that was unchecked) solve all my problems.

Answer 16

Your "My Documents" folder mapped to a network share?

Startup of IIS Express can take minutes instead of seconds if this is the case even if your solution is local instead of on the network share. In regedit.exe, verify that HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User ShellFolders\Personal is pointing to %USERPROFILE%\My Documents.

If it's not, change it or ask your network admin to make an exception to your policy.

Answer 17

I experienced the same problem and tried most of the resolutions above. Simply deleting cache and temp files end up working for me.

Try removing the contents of these two folders:

C:\Users\\{UserName}\AppData\Local\Microsoft\WebsiteCache

and

C:\Users\\{UserName}\AppData\Local\Temp (in particular the iisexpress and Temporary ASP.NET Files folders).

This can be set up to happen automatically on logging on to Windows by adding a cmd file to the C:\Users\\{username}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup folder with the following content:

rmdir C:\Users\\{username}\AppData\Local\Microsoft\WebsiteCache /s /q

rmdir C:\Users\\{username}\AppData\Local\Temp /s /q

Answer 18

None of this worked for me but I found a Breakpoint on a symbol that was deleted. Seems 2010 was hanging on it. To see if this is your issue do debug->windows->breakpoints If any are in there just delete them.

Saunders, mentioned he checked for that but it was not mentioned in the solutions for this problem. Maybe common knowledge for some, but not all of us.

Answer 19

This might help someone, I had the same issue and found out that i had SD card with drive e:\ After removing my SD card the problem was fixed

Answer 20

Each time I recompiled to local host while developing it took several minutes. It was terribly frustrating. After trying umpteen fixes including putting it all on an SSD. I found what really worked. I created a ramdisk and put the whole project in it. Recompiles to local host are now under ten seconds. Perhaps not elegant but it really worked.

Answer 21

In my case it was

Tools/Options/Debugging/General/Enable JavaScript debugging for ASP.NET (Chrome and IE)

Once I unchecked this, my debug start went from 45-60 seconds down to 0-5 seconds.

Answer 22

For me it was that I was debugging in Managed Compatibility Mode. In Tools -> Options -> Debugging -> General at the bottom, un-check 'Use Managed Compatibility Mode'. Debugging became instantaneous where it used to take up to a minute to step through one line. I suspect that's what the 'Managed' means in OP's snippets above.

More on that here: https://blogs.msdn.microsoft.com/visualstudioalm/2013/10/16/switching-to-managed-compatibility-mode-in-visual-studio-2013/

Answer 23

Please make sure you haven't opened Visual Studio in administrator mode

I faced this issue and had to run in normal mode.

Answer 24

I finally fixed (or at least, improved a lot) this problem by making this changes in the local IIS configuration:

1. Open IIS configuration
2. Click into applications pools
3. Right click into each pool and open advanced configuration
4. Make sure that "Enable 32 bits apps" is set to TRUE and Startup mode is set to AlwaysRunning

Hope this helps someone, because I was starting to go crazy trying to fix the slow debug problem

Answer 25

My solution was simply to reload a saved GOOD (backup) copy of my settings (made a year ago). Worth trying before resetting everything to blank. My VS2010 would take 60 seconds to start debugging and approx. 3 minutes to stop debugging. I saved the corrupted settings and to my surprise they were over 3MB instead of 260Kb. I loaded the good backup copy and everything is great again :-)

Answer 26

For me the problem was Avast Antivirus. I uninstalled it and ran with Windows Defender instead and everything works fine. In my solution I only had this problem when running Windows applications, either WinForms or WPF. It was never slow on web applications for some reason.

Answer 27

A quick and easy solution for those who don't have much deviation from default VS settings.

Tools-->Import and Export Settings-->Yes, save my current settings-->Visual C#

I am sure the above solution would work with other default settings too. In my case something messed up with my symbol loading settings but I could not fix it even though I tried quite a few of the suggested solutions.

Answer 28

I set up my Visual Studio in a new job with C# as the default language. It hadn't yet dawned on me that I was doomed to be programming in VB.

I forgot about the C# default because VB seemed to work fine. However, stepping through code was taking a ridiculous amount of time. After trying a number of fixes, in desperation I changed the default language to VB... bingo!

If you've got down this far, it's definitely worth a try.

Answer 29

I was also facing this issue, below are the steps that I perform and it works for me always:

• Deleting the solution's .suo file.
• Deleting the Temporary ASP.NET Files (You can find it at find it at %WINDOW%\Microsoft.NET\Framework\\Temporary ASP.NET Files)
• Deleting all breakpoints in the application.

Answer 30

Restart your computer

I know it sounds far too simple but it was the only thing that worked for me.