Suddenly getting "database error 1193" when processing

[Mamadog]

I'm using phplist version: 2.10.13 and got this error message today:
Database error 1193 while doing query Unknown system variable 'SQL_BIG_TABLES'

I'm getting the processing info as usual but haven't received messages in my gmail account (where I normally send a copy to).

Haven't used the list in about a month and it was fine until today. Were there any updates done to cause this error? Is there anything I can do to fix this error?