I had upgraded from the last version of the plugin, so when i did that, it didn’t update the database.
From the author Mike, (who was very helpful):
Basically you want to make sure there is a permissionLevel field in the _rsvpCustomQuestions table and the table _rsvpCustomQuestionAttendees exists.
So to fix it, i added the permissionLevel field to the proper table. Here is the sql details from the install file:
$sql = "ALTER TABLE <code>$table</code> ADD <code>permissionLevel</code> ENUM( 'public', 'private' ) NOT NULL DEFAULT 'public';";
I added the field and now everything is working again.
thanks for the help Mike!