LibreOffice locks up if two or more files open at the same time

[Penname]

I use Linux Mint Cinnamon. Libre Office (5.1) has been running fine for a number of years.

Over the past few months however, if I open more than one document at the same time, it often locks up, telling me it’s not responding, do I want to wait or stop it running? Waiting does nothing, so I have stop Libre Office.
It’s usually when I have a couple of text documents open.

Now I’ve found that when I restart it, the recovery of, say, a 15 page document takes an hour.
Sometimes they are .docx, but not always.

[Hrbrgr]

…they are .docx,…

Do you use DOCX just because you like it or is there an idea behind it that we don’t know yet?

---

…Libre Office (5.1)…

Please use a current version, thank you.

Download LibreOffice

[Penname]

I often use .docx because that’s the format a client sends them to me for proofreading. I need to return them in the same format after editing.
I save my own text docs as .odt

Thanks, I will download the newer version. I can see it’s 7.2.5.
I don’t know why my Mint update manager hasn’t updated it?

[Penname]

edit1:
I have (I think) installed 7.2.5, but I’m not sure, as the terminal doesn’t give any info in plain English.
All I can say with certainty, is the very last line has changed from white to blue type.

When i go to Office, I can see I have two lots of programs: 7.2.5 plus the original version is still there also.
I clicked on Libre Office 7.2 Writer. It appear to start, then disappeared completely - it doesn’t seem to be running anywhere.
If I click on the old Writer version, that runs.
Have I done something wrong?

edit2:
I have even tried installing the previous version 7.1.8 - just in case.
Still have the same problem: It appears to start running the program for a couple of seconds, then disappears and doesn’t run.
I think I may have to reinstall the version I had before - 1.5, unless you have another suggestion?

[Hrbrgr]

I myself use Windows 10 and 11, so may not be any help for the installation process.
But you can look here how the defaults are:

Installation Instructions / Linux

[Penname]

Thanks for your ongoing help.

I have Cinnamon 18.3 64-bit. Libre Office 7 will not work.
I have managed to install Version 6.2.8.2 and it seems to work OK.

On the older version of LO (1.5?) I had LO Language Tool extension installed.
With Version 6.2.8.2 in Menu>Tools>it shows Language Tool installed, but clicking on it shows nothing there.
I tried to install Language Tool 5.6. That says I have a previous version already installed (extension manager shows nothing at all).
I opted with 5.6 to overwrite the old one and install 5.6. That throws up an error.
I have a screenshot of the error, but I can’t see if I can post it here?