Error Message

Just recently, every Storyline file I try to open gives me this error message "The file "insert file name here.story" is being used by another process or you do not have the proper security permission to access this resource. Make copy of your project file, then try to open the new file."  Ok great, so I copy the file from my F: drive to my desktop and try to open it and I get another error message saying that file has gone corrupt. 

This isn't just one file, it is happening to every file I've tried to open in the past two days. 

What is going on here? 

And, most importantly, how do I fix this?