Some cells may be protected. try highligh entire sheet by press the gray
button between A and 1, then go to tools menu under protection and unprotect
the sheet.

"Cynthia" wrote:

I cannot insert cells into my worksheet. Also data disappears when I cut and
paste cells. Not all data but random cells in the selection. Anyone know
why and how to fix this problem. I use Excel all the time and have never had
this problem.