LibreOffice writer stops working in the middle of writing
 

So, it just stops working, i.e. it gets frozen, I cannot write or edit text all of the sudden. When I close it (force to close), and try to reopen it, the window for reparation appears. I click on repair, and it seems to work. But once I have to click on "finish" - it doesn't. It struggles to do something, but ultimately fails and asks me if I want to wait longer or to shut down "soffice".

How do I solve it, how do I get it to work?

extremely hard to say anything without details. It can be low on resources (like disk full, out of ram, whatever) or a permission issue or hardware defect or something else.

disk and ram are not the problem, I don't know about "whatever".
Which details do you need?