Errors on copying and pasting

Copy and paste of a theme into "empty except for rests" included the rests into bars which I copied music into producing such errors as "Bar 33 Stave 4 Incomplete Expected 4/4 Found 30/16". Se attached text file/
The additional rests could not be removed by highlighting and clicking delete. See picture of faulty bars.

How do I remove the unwanted rests?
Thanks
DonH NOT FOUND: MuseScore 3 error on trying to open.txt