Hi Irina Christodoulou-Pipis

May I please ask that you check if the ENG into EL is in a flavour of languages that match your project settings. Example being if your project is EN-US your TM should be EN-US.

You can check language variants by opening your TM in the Translation Memory Maintenance view and while you have it open, please check the state of your TM. 
Does it have a warning sign alongside its name? Does its index stats need to be recomputed?

Another thing to check is, where is this TM located? Local to windows?

You are welcome to share TM with me if you want me to have a look.

Lyds

Hello Lydia and thanks for your reply of a few days ago.  I thought I managed to resolve the issue (before your reply struggling with the help of my general IT specialist who does not know anything about Trados unfortunately) but in fact today when I tried to work on a new document the same message appeard i.e.The Translation provider ENG into EL TM.sdltm could not be opened and has been disabled.  I tried using the TMRepair App and after the "repair completed" message the same thing happened and this Translation memory is no longer in the list of my Translation memories in Trados now.  I am not very good at IT issues myself and I don't think I can resolve it on the basis of the instructions above, but if you can arrange a session in teamviewer that would really be helpful.  I am running very much behind my work as a result.

I have sent you a PM Irina Christodoulou-Pipis so we can help further 

Hi Lydia

I was wondering whether you actually had any time to deal with my problem TM which I shared on sharepoint. I am still struggling. thank you irina