Saved Files Won't Open - Osx

I am having problems opening my saved Evolve files. I keep getting the message, The file named____was not found.

To try and solve the problem I updated my software to OS X 10.10.4  and installed solidThinking 2015 4945 but the problem still occurs.

Is there as special protocol for saving files that I should know about?

Can anyone help with this problem?

Cheers. Lenin.