Unable to open an existing project " an error occurred while trying to determine the file version"

Question

Hello, 
 (TRADOS 2015) 
 I was working on a 48-files project and I am currently at the 43rd, so today I closed TRADOS 2015 normally, and now that reopen it the project is not there (in the project window). I go to Open project -> Select the project and then I get the error "an error occurred while trying to determine the file version" 
 I reboot my PC and issue persists.

Any ideas? I do not want to lose the already finished 42 files :/

Oana Nagy · Answer

Hello Jose De la Hoz , 
 The main cause for such an error is a corrupted template. 
 I would suggest using a different template. 
 Please follow this article to resolve the issue (ensuring you navigate to the 2015 folder instead) 
 https://gateway.rws.com/csm?id=kb_article_view&sysparm_article=KB0029892 
 It might also be worth noting, as you also have Studio 2017 available in your account (free upgarde) this might be an ideal opportunity to upgrade as Studio 2015 is no longer suppported and you will be able to benefit from the extra features in Studio 2017

Trados Studio > 1. Trados Studio

Unable to open an existing project " an error occurred while trying to determine the file version"