Had a nasty problem yesterday with my debugger. The error I was getting was:
Auto-attach to process '[3172] aspnet_wp.exe' on machine 'JTHAKE' failed. Error code 0x8013134b
I was looking at permissions, restarting IIS changing the user in the
machine.config with no joy. Then by off chance looking at a
blog post
I found out that for some reason my app had changed from running 1.1 to
2.0! I wasn't changing anything in my environment last night so not
quite sure why that happened! So watch out! Microsoft Gremlins at work!