Error With Protect Sheets
The Error was introduced on 08/25/2017 in Office 365 ProPlus Excel 2016 version 1708 (build 8431.2046), as shown below.
The error occurs when some range of cells as "Unprotected" are selected and this selection is change to “Protect”, making a "Select Locked Cells" and "Select Unlocked Cells" options unchecked, the sheet will be blocked all together. The user can’t click on any cell. However, by right clicking on any cell, the Clear Content option will appear, and clicking on it will clear the cell that was previously unlocked from the protection, losing the data and invalidating the sheet protection. Another important point is that if you select a cell or range of cells unprotected by the Name Box, it lets you do the same procedure and clear several cells at a time.