Cut/Copy problems in LO

Okay, I've had the cut/copy/paste issue pop up again in LO. It just
happened today. By way of reminder, my configuration is as follows:

Sony Vaio laptop
Linux Mint 18
LO 6.0.3.2

Today, I was working on an LO Impress presentation. I was also running
LyX, Geany (text editor), Xiphos (Bible software) and Nemo (file
explorer). I wanted to move some text on one of my LO Impress slides.
All I was trying to do was move the text to another location on the
slide itself. I selected the text and pressed Ctrl-X to cut it. It
didn't cut. I then clicked on the Edit menu and both "Cut" and "Copy"
were greyed out as if I hadn't even selected any text. I tried some
other functions, such as applying boldface to the selected text, and it
worked, so LO recognized that I had, indeed selected text. It just
wouldn't let me cut or copy it to the clipboard. Both Ctrl-C and Ctrl-X
did nothing and the mouse options on the menu weren't available.

I then went into both LyX and Geany to see if, perhaps my issue was OS
related. Both LyX and Geany allowed me to cut, copy and paste. I could
cut and copy within LyX and Geany and across the two programs. I could
also paste text into LO from LyX or Geany without problem.

So, the problem seems to be that, for whatever reason, from time to
time, LO stops allowing a user to cut or copy text to the clipboard (or
whatever Linux calls it). When this happened today, as in the past, I
was able to solve the problem by closing out the Impress presentation
(without closing down LO completely) and reopening the file. Once
reopened, I was able to cut and paste within LO again.

Curiouser and curiouser.

Virgil

I (the original poster) have been quiet about this, but actually, the problem is getter worse with time and by now
makes working (translation) uncomfortable process!
The problem occurs ONLY with Libreoffice, but not with any other software as far as I can tell, using at least three
different versions: older version 4..somenthing, intermediate verions 5.2.. and the newest 6.0.5.2.
Once the problem pops up, I have to try all sort of things like deliberately saving all open files, repeating the copy+paste procedure
several times among different softwares, or, as Mr. Virgil said, close down LibreOffice. Usually Write alone WILL NOT be sufficient.
AND .. it does not make any difference whether I use keyboard commands or the mouse.

So, whatever this is ... it has developed into a real pay in the neck.

By now, the situation has developed into a nightmare!
There is nothing wrong with my operation -> it works just fine with other software.
The problem starts mostly when I use memoQ (a CAT tool):
Copy a section in memoQ -> move to Writer -> paste that section.
It may work ONCE - but then never again.
The exact same procedure, except for copying into a text editor or even MS-Word does NOT cause any problems.

What is this with LibreOffice?
Is there really nothing that can be done?
(I do NOT want to use Word and by now I have mostly forgotten how to use it anyway. That would make work very uncomfortable.)

Thank you.
Thomas

Grabbing at straws here, does it make any difference if, when you paste into Writer, you paste special>unformatted text.
steve

No, unfortunately it does not.

Have you tried

Copy a section in memoQ -> start notepad -> paste that section into notepad -> Copy that section from notepad -> move to Writer -> paste that section into writer

Alex

That does NOT help. The result is (almost) always the same.
I tried similar tricks a million times already.