A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
The Paste problem is a widely reported bug in Excel as being caused by an Office update (KB5002914), Microsoft have indicated they are aware of the problem and they are working to resolve the problem, they already released a patch for Excel 2016, but not for other office versions yet.
In the meantime, most people indicate two workarounds will work until a patch is released.
1
Instead of copying the data, press Ctrl + X to cut the data, then press Ctrl + Z to undo that action, then you should be able to paste the data.
2
Or, copy the cell(s) and use Paste Special, and use that to either paste data or formula, depending on the data you have copied