alexander pace 

What is causing Studio to shut down?

I dont understand what you mean by 

alexander pace said:

the time of File Trados Proj is reading the time when Trados shut down.

But I do understand that your SDLXLIFF Files have not been saving your work so you feel that you are loosing your work.

Trados Studio is set to AutoSave every 10 minutes  - so not ALL should be lost. Only the last 10 minutes

That said, where is your project saved to? 
Are you using things like Dropbox / OneDrive?
Or is your project saved locally to your machine and your access to the project is local.

Lyds

saved in a folder on desktop

Lydiea said I dont understand what you mean by the time of File Trados Proj is reading the time when Trados shut down.

Alex: it means when i go and retrieve my work after trados shuts down on its own and I go in the desktop folder where i am saving my work the  Trados File Proj is reading the time when Trados shut down and Xcliff the time when I first saved the file in desktop folder i.e it is not saving all the work done between opening the file at the beginning of reviewing and when Trados shuts down on its own. I can send a screen shot if it is possible here

Moreover the delete all messages button is not enabled either 

alexander pace 

alexander pace said:

saved in a folder on desktop

This could still be OneDrive.  What's the full path to this location?

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Lydia Simplicio fyi.