I'm puzzled that you had to reconstruct your KBD file outside of XyScript to get it working -- especially since you never complained about having trouble editing your KBD file before now.
If you're puzzled, imagine how puzzled I am! To clarify, with the kbd file open, editing by placing the modified QUIT command (ctrl+shift Q :45=SaveCM $XSDIR/cm-history.xpl;QUIT) on ctrl+shift Q (replacing, and commentingdecide to use it, then attempting to save, that's when I got the OS error. At that point impatience prevailed and I went outside to get it to work. And many thanks for calling my attention to XE. I'd seen that in the manual but like so much else, it went to the back burner. FW