Created attachment 74869 [details] Test file This file was edited with LO 3.4 / 3.5 / 3.6 and untill now I didn't have problems with it. Document has write protected cells (almost whole document), but area from B10:AH49 is not write protected. 3.6.5 can open this file and write to mentioned area. 4.0.0 can open this file, but most of cells from mentioned area B10:AH49 are write protected.
Looks like it is related to a bug fix. We now correctly handle cell protection from conditional formats which was not the case before.
What does conditional formats have to do with cell protection!? Cell protection was defined on cell by cell basis, not conditional formating.
Cell protection is also a style property. Since conditional formats apply styles to cells they are also responsible for applying cell protection to cells.
*** This bug has been marked as a duplicate of bug 58826 ***