updating EE2 to EE3, script error: Integrity constraint violation 1062 Duplicate entry

I’m trying to update an EE v2 site to v3, eventually going to v6.

It gave this error after running the 3.0.6 update script.

Error While Updating 3.0.6 to 3.5.17 Stopped | Step 2 of 3
Oops, there was an error
An unexpected error occurred while performing the update

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'chargpoint' for key 'PRIMARY':
ALTER TABLE exp_super_search_terms CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci

I saw a different but similar error elsewhere it mentioned this as the possible cause:

“Mysql throws this error because the field type of the auto increment field is not large enough to hold the next value, so it tries to wraps the count back to ’0′ where the is already a record with that value.”

What could be the cause, and the solution?