I have tested this with 4.0.1.0+ (Build ID: a560ee1625393faf5cd5e04c356a9101b701542) When deleting the contents of a cell by pressing the key "Del" on the keyboard, the conditional formatting for that cell is also deleted. I don't think this is meant to happen because the UI doesn't reflect this change: the cell keeps its color. Also, when pressing "Undo", the contents of the cell are restored but the conditional formatting is not. This can be verified by checking the region in Format -> Conditional Format -> Manage... You can use the test sheet from #59843. Strangely enough, on that sheet you have to select two cells and press delete, otherwise the format stays correct.
Cannot reproduce on 4.1 master. You marked RC3 as the version that you tested against but then you put 4.0.1.0 which is RC1, have you tested against RC2 and RC3 as well? Also, you didn't say what operating system you're running. My test: Version 4.1.0.0.alpha0+ (Build ID: 027bb41aa16793e88e9fc1b3550c8c893363647) on Bodhi Linux Marking as WFM as my version is newer. If you have tested this on RC3 as well, please reopen the bug. If the oldest release that you have tested on is RC1 and you have also tested on RC3, please change the version to 4.0.0.1 rc, as Version is supposed to be the oldest version that you have seen the problem, not the latest it has been tested.
I think you are confusing version numbers. 4.0.0.3 is rc3 and 4.1.0.0.alpha+ is master. However, I have been using 4.0.1.0 (!), which is not available in the Bugzilla dropdown - that is why I added it in the comment. This version is supposedly later than rc3. But I have now also installed and tested with Version 4.0.0.3 (Build ID: 7545bee9c2a0782548772a21bc84a9dcc583b89). Indeed, this version is older than my 4.0.1.0, because not only can I reproduce this bug, #59843 is also still in it. Sorry that I overlooked the operating system, I added it now and reopened the bug.
Created attachment 74297 [details] spreadsheet used for test Hi, I reproduce, use the attached file and follow the instructions in the sheet. Note that according to the document used, it is not always necessary to clear the whole area, sometimes a few cells are enough. Version 4.0.0.3 (Build ID: 7545bee9c2a0782548772a21bc84a9dcc583b89) - Vista and also with Version 3.6.5.2 (Build ID: 5b93205) - Vista It works fine with 3.5.7.2 It might perhaps be good to change the version of the bug?
(In reply to comment #3) Sorry, I reversed the colors for point 2, please read: 2) initial checks : 1 is in A1 : A3:C7 - > background red ok enter 0 in cell A1 A3:C7 - > background yellow ok
*** This bug has been marked as a duplicate of bug 57661 ***