file is being used by another process

Hello!
I am experiencing issues similar to the issues users encountered above on this thread. When I attempted to open my project from a shared drive, the error message "The file 'filename' is being used by another process or you do not have the proper security permission to access this resource." appears. 

I closed all open programs, restarted my computer- still got the same error.

I then copied the project to my desktop. When I opened it from the desktop, the error message became "The project is invalid or corrupt and cannot be opened. It may have been created in an earlier version of Storyline." 

I changed the file name on the desktop, tried to re-open...and go the same message.

Please help! Any advice?? I don't know what to do if I lose this entire project...