I experience a strange behaviour in Visual Studio 2010 when creating Windows Phone 7 apps. After some time VS starts to complain about Invalid XAML although there is no problem and the app compiles and runs just fine.
It bugges me because I cannot use the visual desingner saying “Exception was thrown on “DataTemplate”: Invalid XML” and there is a DataTemplate higlighted in the code. The data template is always ok, VS does not complain about it when copy-pasted to another project.
I found out that problematic are usually the DataTemplates with custom converters or when usin g classes like PhonePerformance.
Sometimes the error is “Exception thrown was due to document error: Invalid XML” and nothing is even highlighted in the XAML file.
I tried reinstalling .NET. Visual Studio etc. and the problem occurs on two separated machines so I do not think it is specific to my configuration. It may be specific to my code.
Anyone experienced similar behaviour?
A friend has found a solution and you would not believe where the problem is. This happens if you have a space in the name of your assembly. I found out that I really have a space in assembly name in all the problematic projects, renamed the assemblies and the designer works again.
The solution is also mentioned here http://forums.silverlight.net/t/115011.aspx/1