how do I return a sheet to it's orginal blank status without having to delete it and insert a new one with the same name.

I'm trying to copy and paste some information in a sheet from another workbook but it's giving me the merged cell error saying "the operation requires the merged cells to be identically sized" and I can't paste, can't paste special values either. I pasted onto a new blank worksheet in a new workbook and it pastes fine. Even though I did a "clear, all" of the sheet I'm pasting to and it still gives me that error, seems like clear all doesn't remove the merged cell format. I can't delete this sheet because it links to a lot of other sheets so I have to paste on this sheet.

I want to know how to return this sheet to a blank status like a brand new sheet. Thanks.