amir_rezas wrote:That's right thanks.
phpbb_ is default value of phpBB prefix !
And I set phpbb_1 and this error occured I think it's bug.
please solve it
It's not a bug.
Your hosts have a 30 character limit on field names.
This field name 'search_wordmatch_un_mtch' is 24 characters long.
That leaves you 6 characters for the prefix.
phpbb_ is 6 characters.
You added an extra digit to make it 7 characters long and your hosts gave you a message telling you that.