I was using a Resharper trial in Visual Studio 2010 that expired. After it expired, Intellisense was broken and a number of settings such as 'Open With' were restored to defaults. I re-enabled Intellisense features that I was familiar with for C# files by checking the boxes 'Auto list members' and 'Parameter information' under Options->Text Editor->All Languages.
I still do not get the autocompletion behavior that I expect within XAML files of my existing solutions. When starting to type a tag, '<', I normally expect to see a list of types that are in the scope of the XML namespace. I do see some autocompletion options, but they are limited to
<?. When typing property names and values I don't get any options.
When I create a new solution with xaml files, Intellisense behaves as expected. I have disabled the few extensions that I have installed to no effect. Restarting VS and my system also hasn't made any difference.
Can anyone offer any methods of troublehooting Intellisense?
Edit: I should also mention that Visual Studio does not prevent me from editing XAML files while debugging in the cases that Intellisense is not working. This may be a good hint at what is going on.
Export your settings under tools -> Import and Export Settings. Do it in groups of functionality. Then use Import and Export Settings to reset all your settings and re-import your settings a bit at a time to figure out where the issue is.