Excel Filling Cells Random

[meppwc]

I have been experincing something randomnly with Excel, on any workbook that I open. While filling in data into cells, all of a sudden a cell with fill with color black. I also notice the in the top left window where "x - checkmark - fx" is present, that it too is filled black. It is easy to fix it when it happens but I am curious if anyone has run into this and how to fix it.

 

[ceranes]

Do you have a screenshot?

 

[meppwc]

 

[meppwc]

This happens when I enter data in a cell. Not all the time, but once every 10 or so entries. The fill occurs. If I rekey the same data, the fill goes away. It is easy to workaround, but a constant nuisane. Tried closing down Excel and restarting, did not fix. Reboot did not fix.