Here is the error in its entirety:

Error while adding
Z:\arcade\support files\Control Panels Daphne\cpanel\ace.png
to
Z:\arcade\support files\Control Panels Daphne done\cpanel.zip
Will you stop the rebuilding process?

Nothing appears in the warnings window until I try a second time, then it says:
Corrupt Zipfile:Z:\arcade\support files\Control Panels Daphne done\cpanel.zip | Reason: UNKNOWN LOCAL FILE HEADER