Sorry, but I can't find my old post on a similar problem, but I know that
someone here has the answer, since it gets asked occasionally:

I have a worksheet that ends in column CD and I want to insert some columns
just to the left of CD but it won't let me insert even one, says it will
push stuff off of page. I have cleared everything to the right of CD, so I
know it is empty.

I seem to recall that:

If any cells are merged, it may balk
If there are any objects, such as cell comments, it may balk
Possibly range names that already extend all the way to the right, but I see
none.

I have eliminated all of these, but it hasn't helped. Is there some other
weird thing I've forgotten?

Thanks!
Dean