File.WriteAllText throws UnauthorizedAccessException

Question

Doing File.WriteAllText to a remote path throws UnauthorizedAccessException. When I open the file in notepad I can edit it without a problem. The process that's trying to modify the file is running as my own user account, so it should be able to access it.

Answer 1

The UnauthorizedAccessException is also thrown if the file has the "hidden" attribute set. Don't ask me why...

Answer 2

According to MSDN, UnauthorizedAccessException can also be caused by:

path specified a file that is read-only.

-or- 

This operation is not supported on the current platform.

-or- 

path specified a directory.

Is it possible one of these conditions is the cause of your problem?

Answer 3

I believe you also get this exception (although its not documented) if the file is being locked by another process or thread.

Make sure nothing else has opened the file in a manner that prohibits writing. Notepad is not a good test for seeing if a file is locked, since it will open a locked file (ie: read-only files are fine).