21765: API Opt-Out/Help Length Invalid

The campaign submission could not be processed because some combination of the following fields had invalid lengths: help_sample_message, help_keywords, opt_out_sample_message, and opt_out_keywords. Please verify that the opt-out and help messages are between 20 and 320 characters each. Also verify each set of comma delimited opt-out and help keywords does not exceed 255 characters.

Help or opt-out messages/keywords are too long.

Limit each message to 320 characters and total keywords to 255 characters.