Error reading CDXML document at line XX: not well-formed or invalid token
Open the CDXML file with a text editor like Notepad ++ (Notepad++ lets you locate the error by the line number).
Look for a superscript “L” in the document and replace it with a space. If using Notepad++, you will see the letters ETX in a black background instead (easier to find).
You may also find other kind of text, but always with the black background.
Mac users who do not have access to Notepad++ can also use Komodo Edit (free) to find the correct line number.
Save the changes and try to open the file again with ChemDraw/ChemBioDraw