I would like to put comments into a provided .dwg file. Unfortunately the "paste" function does not work for both ds text tools. In new files I can easily copy/paste text, and even paste text out of my "corrupt" file. But in the "corrupt" file I only get an error message whenever I try to paste elements.

What could be the cause for that?

When pressing the "paste" button it reads: "LayerTableRecord(1): XDatenelement RegAnw "10C4" Ungültig" (sorry, out of the german version of the programme...), and then "error".