Visual Studio-2017. These projects are either not supported or need project behavior impacting modifications to open in this version of VS

Question

I created a project in Visual Studio 2017. It worked all fine when I initially created it. The next time when I tried to open the same project it gave an error as shown below

I had created that project in Visual studio 2017 itself and the next time as well I tried to open it with visual studio 2017. So doesn't seem to be a version related problem.

Also, I did not make any changes to the project after it worked last time. And when I click "OK", the solution does not load. Below is what in solution explorer.

I tried to research this error a bit and came across some links as below as even I am getting the exact same error as mentioned in those links. But those links didn't really help me. I tried to reload the project solution, but that didn't work.

https://social.msdn.microsoft.com/Forums/vstudio/en-US/966fb9d0-5423-4810-b03b-94a5417831a5/these-projects-are-either-not-supported-or-need-project-behavior-impacting-to-open-this-version-of?forum=visualstudiogeneral

https://www.aspforums.net/Threads/120933/Visual-Studio-Error-These-projects-are-either-not-supported-or-need-project-behavior-impacting-to-open-this-version-of-Visual-Studio/

Answer 1

This problem happens because of the XML element inside the .csproj file (if you open as text / edit the csproj file directly)

<ProjectTypeGuids>

See related questions here:

• The question here is related; the top-voted answer and the accepted answer suggest editing the .csproj file and changing the <ProjectTypeGuids>
  • be careful of changing the csproj; this might only be appropriate if you know what you're doing / using specific Project Type GUID values that are compatible with one another, (see details in the answers above, which seem specific to ASP.NET MVC 2)
• The question here, which shows how to install the correct tooling depending on your project type (the question is here specific to ASP.NET MVC 5 and C#)
  • (My answer on the same question) shows how to lookup the value of the your <ProjectTypeGuids> against this lookup table, to find out what project type(s) your project is, so you can find better information how to support

Answer 2

I got the same error after trying other methods this methods works like a charm for me.

1. open Visual Studio Installer.
2. click on modify.
3. check Game Development With Unity.

install it and here you go.

Answer 3

So, just in case anyone is interested to know, finally what worked for me is,

1. DELETE THE csproj.user FILE that was there in my solution
2. RELOAD the project

And I got the hint from https://forums.asp.net/t/1491251.aspx?Can+t+load+project+because+root+element+is+missing+

Thank you all those who helped me with my issue. Although I was able to solve my problem, if anyone knows, I would like to know the reason why I got that error and why just deleting the csproj.user file and reloading the project loaded my solution all good.

To add to this, when I created this solution initially and it worked all fine, I then shared it with my team member and that team member opened the project all fine and then shared it back to me without any changes. And then when I tried to open it again, I was unable to open the project.