Upgrading CiviCRM from 4.6.26 to 4.7.16 is failing at step Upgrade DB to 4.7.beta6: SQL
with the following error:
ALTER TABLE civicrm_event ADD COLUMN max_additional_participants int(10) unsigned DEFAULT 0 COMMENT 'Maximum number of additional participants that can be registered on a single booking' AFTER is_multiple_registrations [nativecode=1118 ** Row size too large (> 8126). Changing some columns to TEXT or BLOB or using ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED may help. In current row format, BLOB prefix of 768 bytes is stored inline.]
Everything I can find says that this is a fairly fundamental MySQL restriction but I can't find any much trace of people hitting it with CiviCRM at all.
The MySQL server version is 5.5.54 which should be supported, and I have tried increasing the InnoDB log file size from 5Mb to 48Mb as some things say that will help but it made no difference.