Wierd message when accessing FireFox

In the last couple of days, I'm getting a message window when accessing FireFox. The message reads:

Windows cannot access the specified device, path or file. You may not have the appropriate permissions to access this item.

If I erase the message and retry Firefox, it loads. I double checked, and I am the system admin. Any ideas why this is happening and how to stop it?

Welcome to the forum. Its when it says this it could refer to downloads, cache or other you could reset it see if that cures it Reset Firefox preferences to troubleshoot and fix ... - Mozilla Support Community

Samuria said:

Welcome to the forum. Its when it says this it could refer to downloads, cache or other you could reset it see if that cures it Reset Firefox preferences to troubleshoot and fix ... - Mozilla Support Community

It didn't occur to me that the problem could be with FireFox (facepalm.)