Build error: “The process cannot access the file because it is being used by another process”

Question

I\'ve got a C# webforms app, that until today had been working just swimmingly.

Now today, all of a sudden, every time I try run the app, I get a file l

Answer 1

How is your web app configured? Does it run under Cassini (the tray web server) or IIS?

This shouldn't happen normally though. I think ProcessExplorer can tell you what files a process has locked. If not process explorer one of the other sysinternals tools.

One thing to try before even downloading one of the SI tools is to stop the Cassini web server, and seeing if that frees up the file.