AggTable matcher can't find fact count column named fact_count

[cribalik]

I get the error message

2015-12-10 15:32:37,087 ERROR [mondrian.rolap.aggmatcher.AggTableManager] Recognizer.checkFactCount: Candidate aggregate table 'sales_agg_year' for fact table 'sales' has no fact count columns. 2015-12-10 15:32:37,087 ERROR [mondrian.rolap.aggmatcher.AggTableManager] Recognizer.checkNosMeasures: Candidate aggregate table 'sales_agg_year' for fact table 'sales' has no measure columns.

where sales is the fact table and sales_agg_year is the aggregated table, and sales_agg_year contains a column named fact_count of type int. I am using the default rules. I am using MySQL.

the cube definition:

<Schema name="sales agg test"> <Cube name="Agged Cube" visible="true" cache="true" enabled="true"> <Table name="sales"> <AggPattern pattern="sales_agg_.*"/> </Table> ... rest of cube definition .... </Schema>