WPX9 crashes

A provisional result
Now, I am sorry to say that, but WPX9 reacts unforeseeably to screen-saver or sleep mode (hibernation not used/not tested).  Sometimes, WP recovers without issues, sometimes it crashes.  I cannot figure out, which are the conditions for this unpredictable behaviour.  Crashes happen with saved and yet unsaved .wpd documents, with converted .doc(x) documents and other file types; there might be only one document or more documents open.  The size doesn’t seem to play a role.  At least no crashes with a blank screen only.
I don’t think that it is a Win 10 issue, because Windows itself doesn’t crash after unlocking.  Other programs recover as expected from screen-saver or sleep mode. Changing the settings for screen timeout doesn’t really help.  As far as I can say, the problem occurred after upgrading to Win 10.  I can’t remember to have had such issues with WPX9 and Win 7 (on the same machine).  I’m just surprised that this issue seems to be known for years, but hasn’t been solved by Corel, although this annoying behaviour and instability of at least WPX7 till X9 must get on the nerves of many WP users.
The only workaround seems to save a document as often as possible and before the screen-saver gets active.

My computer has had the same issue, including just now!  What a pain, ought to be solved by Corel.  So far though, haven't totally lost any documents.

Many thanks for your reply and for confirming the issue.  (Due to Easter holidays, I’ve been away from my computer.)  Since the problem seems to be quite common and must be known at Corel, I’m just astonished, why they seem unable to fix it.  And yes, the document backup function saved me from total loss of files, so far, too.  But such crashes are no good advertisement for the company and the – all in all – highly regarded WordPerfect program.  Corel must remove this defect, otherwise the slogan »Experience the benefits of a legendary office suite« sounds a bit dated.