Reputation:
I have a console application which has target .NET 2.0
It is very short but full of unsafe code.
I converted it to VS 2010. I run it OK.
When I try to change "target framework" in properties to 3.5 or 4.0 it shows message box:
TargetFrameworkMoniker: Error parsing application configuration file at line 0. XML document must have a top level element.
the target then stays 2.0 anyway.
Upvotes: 27
Views: 21149
Reputation: 19
I faced this problem , i solved it by click app.config to open it and leave it ,then go to properties and upgrade .NET version
Upvotes: 1
Reputation: 7356
For me, my project was using a web.config file that was a linked file back to a web.config in another project. I removed the link, changed the target, then added the link back.
Upvotes: 1
Reputation: 3581
I was trying to retarget from .NET 4.5.2 to .NET 4.5 In my app.config, I had to change
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
to
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
before the project properties page would let me retarget.
Upvotes: 0
Reputation: 21125
This happened to me because my project file was marked as "Read Only" in its properties. Changed it, and it was fine.
It also could be caused by read-only app.config/web.config
Upvotes: 30
Reputation: 909
I have same issue. I solved it by removing write protected attribute of web.config file. It was read only earlier.
Upvotes: 1
Reputation: 275
For me the problem was the web.config file located outside of the project directory. I moved it back in, and was able to change the target framework.
Upvotes: 1
Reputation:
Found the solution. Simply opened app.config in text pad (it was empty for some reason) and pasted:
<?xml version="1.0"?>
<configuration>
<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/></startup></configuration>
Upvotes: 22