Dear Jose Espín 

The error message says it clearly: you are trying to access a file that is located in your temporary internet files! And probably this file has in the meantime been removed, because it is in a folder for temporary files. 
When you receive a package, please save it in a folder of yours, which you control and then open it from there.

This is not a problem of Studio!

Walter

I've done that already, obviously. Same result.

 Jose Espín 

Are you still struggling?
Have you since tried this: https://gateway.rws.com/csm?id=kb_article_view&sysparm_article=KB0038682

Looking forward to your confirmation so we can help you further

Lyds

Dear Lydia, 

Not only I'm still struggling, Trados has stopped working altogether. The thing is that, even if I uninstall it, delete everything related to it, and install it again... It still doesn't work. So the only option that I think I have at this point is to completely format my computer. 

Jose Espín 

I'm just wondering if you use OneDrive or something like that?  If you do can you try placing the package in a folder outside of the OneDrive influence and also create your project in a  folder outside of the OneDrive influence.