This report cannot be faxed..."" appears whenever any report is printed. It's just an aggravation since you can click out of the message and proceed with printing. In my case, this started when the IT Dept. upgraded the printer drivers.
Sage KB says to:
~Check the Default Printers in LM > Main > Preferences,
~Make sure the Fax is not the Default printer, and if still persists then
~Uninstall and re-install Workstation Setup.
None of these worked for me. What did work I noticed that in Report Printing > Setup button, when selected the Fax was the first printer in the list even though a different printer was the Default. I went to Start > printers and checked the Fax as the Default and then rechecked the actual default printer which eliminated the fax message. And the Default printer is now first in the list.