Thanks (3.9) cant active on 1.6

[F@RUK S]

This user has been denied support.

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE Key_name='adduid'' at line 1
Query:
SHOW KEYS FROM mybb_thx WHERE Key_name='adduid'