Solution
The other fax machine did not respond within 35 seconds.
Send the document again. Contact the other party and have them check their fax machine. If you are making an overseas call, add a pause to the number.
The other party may not be using a G3 fax machine.
Check with the other party and send the document to a G3 fax machine. If the other party does not have a G3 fax machine, try sending your document using a transmission mode the other party's fax machine supports.
