In every ways (menu or mouse clicking on icon) trying to edit conditional format on cells or row or lines push Calc to freeze : all functions are greying and nothing else happen even after 1or 2 hours.
This happens on Windows 11, libreoffice 24.8.6.2 (the LTS version !) on a sheet created on libreoffice Calc only.
I may have opened it on libreoffice Calc under Linux (but in LTS version too) but that’s all I have done to it…
First, don’t be upset, it’s not the biggest problem in this crazy world. Second, try Alt-Tabbing and look at the list of windows. Maybe the modal window, the form for editing conditional formatting, opened normally and is waiting for input. At the same time, the document window has become temporarily unavailable. Usually, the modal window is drawn on top of the document, but right now Windows decided to place it below or even beyond the edge of the screen. This is only a guess, but it’s worth checking.
thank you for answering ;)… and sorry for my english (not my native language !)
I’m not that upset because there is no new window appearing …(Alt+TAB already used ! ). For me, it’s clearly a bug…
I tried to do the same thing under linux with the “fresh” version of libreoffice with a copy of the original file and I ended up with the same result. The passage in modal mode try to happen but nothing more, I can select a cell with the mouse (the border gets blue !) and that’s all i can do in libreoffice…
And some of the menus become unavailable (format, Styles, sheet, data…) and the others still reacting are truncated… Ctrl+W doesn’t work.
What about Esc?
By the way, in In every ways (menu or mouse clicking on icon) you say about which menu? Format - Conditional - Manage? It looks like this window really isn’t displayed by Alt-Tab. Most likely the manager window is there, but somewhere outside the screen. And yes - this window doesn’t close by Ctrl-W
Yes Format-Conditional-Manage or mouse clicking gets me the window where I can choose wich line/cell/row I want to edit to appear. and it appears but after I have selected the cells, they get their blue borders and nothing more happens…
I just spammed Esc 
the window for editing re-appears !! and I believe/know there is a problem in where some of the cells are selected 2 times with a conditional format…
I have erased the faulty part and It seems to be interactive again…yes, as I read it there is a lot of new conditional format that have spawn on their own. Thank you for Esc 
Now, I will correct all those faulty formating …
and it doesn’t completely solved the problem. there is a window that get concealed somewhere, as I’m working on a multi-monitor machine. You may be right ! It doesn’t spawn on a visible part of the screen. And now it’s not a libreoffice problem but more of a windows problem… Once again thank you especially for Esc !