I am attempting to create a simple silverlight 4 application in visual studio 2010 ultimate running on windows 7 x64 and I am unable to use f5 debugging.
The error is:
Unable to start debugging. A fatal
error occurred. For more details,
please see the Microsoft Help and
Support web site. HRESULT=0x8004005.
In researching this I see a few people who say that reinstalling the developer runtime will correct the issue. I have done this several times but the issue remains. I have also tried running without debugging (works fine) and then attaching the debugger to the ie silverlight process, however this doesn’t work either (it only breaks on the ‘throw new Error(…)’ javascript eval code.
I can do f5 debugging of asp.net projects without issue.
I have looked at several other silverlight debugging posts and either their error is different or their solution did not work for me.
This appears to have been caused by a windows phone 7 tools beta. By uninstalling it and installing the rtm version, the issue went away. shrug