Error caused by nonexistent column

I have these measures in the mbammsreportshare table:

1. Quarterly Shares = COUNTROWS('mbammsreportshare')
2. Meets Quarterly Share Goal = calculate(IF( [Quarterly Shares] >1,1,0))
3. Count of Acct Mgrs = var numshares =
   CALCULATE( 
   DISTINCTCOUNT(mbammsreportshare[acct_mgr_name]), filter(mbammsreportshare,[Meets Quarterly Share Goal] =1 )
   ) RETURN numshares

The third measure gets this error:

The query referenced calculated column 'mbammsreportshare'[access_count_num] which does not hold any data because there is an error in its expression.

If I remove the filter from the last measure it doesn't have the error.

There is no access_count_num column in the mbammsreportshare table or any other table.  There is a column called access_count in mbammsreportshare.  It is not used by any of the measures.

What could be the cause of this?

Thanks for your help.