Error mysql real query

[Harkenzord]

Hello guys, good morning.

Today after some hours running my server, this error appeared:

[error - mysql_real_query] query: select reason, expires_at, (select name from players where id = banned_by) as name from ip_bans where ip = 1076197311

Any idea how can be fixed and how it happens?

Thanks for any help, apreciated.