I am getting the following error message when trying to setup a select_single field in forms configurator and linking to a lookup table.

"Table/view technol, form configurator, unexpected primary_key_table_field: projects. Check $form_config_security_check in config.php for additional details."

If I change $form_config_security_check from 1 to 0 in config.php then this solves the problem but config.php warns against doing this.

config.php says "For the parameters in form configurator involved in queries execution, such as "Lookup table name" or "Lookup table primary key field", DaDaBIK checks if they contain proper table and field names and if not, it throws an error"

The lookup table I am using is called project_managers with the field names below. I don't see why these would cause an error. When I try a different lookup table I get the same error.

1Joe Bloggs
2Mickey Mouse
3Donald Trump

Any idea what I can check to try to resolve this?