Suddenly I can't open documents in LO Writer. They start to open for a fraction of a second and then disappear. Can someone help with this? Thanks.

[Falconer]

Also, a small translucent red icon of a book appears in the middle of the screen (?)
And after I try to open a document, and it disappears, if I right-click on the Writer icon, the document will be listed as open. But I can’t see it.

[ajlittoz]

If you want to obtain useful answers, mention OS and LO versions. More over, this is no tutorial but a personal question, you should not have posted it as wiki.