+1 also occured to me, I ran the same with 60 instead,
ALTER TABLE users modify COLUMN first_name varchar(60) NULL , modify COLUMN last_name varchar(60) NULL ;
which worked although when I do a quick repair the system still recommends I run the command again?
Notice: Trying to access array offset on value of type null in /home/encorese/suitecrm2.encoreservices.eu/include/utils.php on line 1845
Notice: Trying to access array offset on value of type null in /home/encorese/suitecrm2.encoreservices.eu/include/utils.php on line 1799