Description:
Hi. I have a problem in Libre Calc. Until recently I was using Open Office, then switched to Libre in the hope that Libre Calc didn't have the annoying but that Open Office Calc repeatedly demonstrated, only to find that Libre Calc has a very similar bug. In fact, I suspect it is the same bug but that it manifests slightly differently in each of the two programs.
My environment is Windows 10 latest release (although the bug manifested in Open Office through multiple releases of Windows 10) on a 6-core laptop. My version of Libre is
Version: 6.3.5.2 (x64)
Build ID: dd0751754f11728f69b42ee2af66670068624673
CPU threads: 12; OS: Windows 10.0; UI render: GL; VCL: win; 
Locale: en-AU (en_AU); UI-Language: en-US
Calc: CL
I have a huge and very complex spreadsheet wich I am continually working on and enhancing. Most often the bug shows up while using it, but I have had the bug show up in Libre while I was using another, very small and very simple spreadsheets after I finished using the big, complex spreadsheet and had closed it without closing Libre Calc, then started using the small, simple spreadsheet that I had had open for a while at the same time as I had had the other huge, complex spreadsheet open.
In Libre Calc, the bug manifests as the right-click menu and the pull-down menu lose their text after I've been working in the spreadsheet for a while. The menu commands still work using the keyboard (eg, ALT F A for file/ save-as), but you can't use the mouse to click on the menu items because the menu item text is missing from the menu window and you could be clicking on anything. I suspect that if you knew whereabouts in the window the function you wanted was, you could probably click on it and it would probably work, but I haven't tried doing that because whenever the bug manifests, it is when I really really need to save the file because of the changes I have just made to it.
In Open Office, the bug manifests slightly differently. In Open Office, when you click on the File menu, you can see the text in the menu window, but when you click on Save-as, nothing happens. Save works when you click on it, but not Save-as.
The bugs manifest in each program after about the same amount of editing in the spreadsheet, so I think the cause of the bug is the same in both programs. In other words, I think the bug is in code that is common to both programs, even though it manifests ever so slightly differently in Libre Calc than it does in Open Office Calc.
The fix in both programs is to shut down Libre/ Open Office totally and restart it. I usually restart the computer at the same time, just to make sure. I tried reinstalling Open Office to get rid of the bug at one stage, but it made no difference. After restarting Libre, everthing proceeds normally while using that big complex spreadsheet for a while, then the bug reappears and I have to restart Libre again in order to continue working on the spreadsheet. Fortunately, in Libre Calc, it is still possible to save my work using ALT F A before shutting it down.
Unfortunately I can't give you any instructions that will allow you to replicate the bug, because the bug is triggered by the amount of editing I do in the spreadsheet, not by what I do in either Libre Calc or in the spreadsheet. The problem always shows up about the same amount of time after I opened the spreadsheet in Calc.
I believe that the most likely cause of the problem is memory housekeeping. I think memory is being consumed for some particular task and not being released for reuse when it should be.
To date I have seen no adverse consequences for the contents of my spreadsheet model as a result of the bug in either Libre or Open Office. The bug doesn't seem to corrupt any data when it triggers, thank goodness. And the fix is simple - just close and restart Calc. But it is a very annoying bug, and it would be nice to have it fixed.
Kind regards
Malcolm

Steps to Reproduce:
1.Open a huge, complex spreadsheet
2.Edit various fields and formulas for a while
3.Bug appears.
4. Close Calc and reopen it with same huge, complex spreadsheet
5. Edit various fields and formulas for a while
4. Bug appears. Bug is triggered by the amount of editing done, not by what editing is done.
Bug has been appearing for months in Open Office Calc. I switched to Libre in the hope of getting rid of the bug, but bug is present in Libre too, but manifests itself very slightly differently. (But in a way that is much easier to live with than the way it manifests in Open Office.)

Actual Results:
Once the bug triggers, menu window lacks any text, whether it is a pull-down menu or a right-click menu.

Expected Results:
Until the bug triggers, pull-down menu windows and right-click menu windows are populated with commands that one can left click on. After the bug triggers, there is no text visible in the menu windows and to control the program, one must use the keyboard functions.


Reproducible: Always


User Profile Reset: No



Additional Info:
Open Office has an almost identical bug that is triggered by the same amount of editing in the same huge complex spreadsheet. It manifests very slightly differently in Open Office than in Libre, but I believe the root cause is common to code common to both programs. I believe the problem is memory housekeeping. I believe that something is consuming memory and the memory isn't being reused when is is available for reuse. The more editing done on a huge, complex spreadsheet, the more memory allocated for some particular task is consumed, until all the memory allocated for that task has been used and none is left, then the bug triggers.
Version: 6.3.5.2 (x64)
Build ID: dd0751754f11728f69b42ee2af66670068624673
CPU threads: 12; OS: Windows 10.0; UI render: GL; VCL: win; 
Locale: en-AU (en_AU); UI-Language: en-US
Calc: CL

Open GL ver 4.6.0 Build 26.20.100.7262 is installed with Intel Graphics Drivers 26.20.100.7262 9-25-2019

Microsoft Windows 10 Pro with 8 Gb RAM Intel  i7-8750H CPU and intel UHD Graphics 630 renderer.

I haven't tried resetting my user profile because I've finished working on that spreadsheet model for a while and have nothing more planned to do in it for a while.