HELP! Club Website has a Problem! Software Error!

Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/public_html/fth/html/libraries/kunena/External/Nbbc/src/BBCode.php on line 1435
When a club members tries to log in to our club website, the following message pops up:Software error:GetRowsAsArrays_DBI[AGENDA](Callers=>main::GetRowsAsArrays_AgendaDB>main::GetToastmaster_AgendaDB): Unable to execute query: [SELECT MEMBERID FROM AGENDA WHERE MEETINGID=? and MEMBERID>0 and ROLE like '*Toastmaster%' order by ASEQUENCE (Bind Values=2044434)] Error=[Incorrect key file for table './srvadmin/AGENDA.MYI'; try to repair it]
For help, please send mail to the webmaster (), giving this error message and the time and date of the error.

We have a club meeting tomorrow, and we would like to get this fixed ASAP!

We always require your club number to assist you.

Okay it's actually working now. I'm not sure what happened