Symptoms
If a query that returns many bit columns is run as a parallel query and the row size passed through one of the Parallelism physical operators in the plan exceeds approximately 8 KB in size, a handled access violation may occur.
Resolution
A Parallelism physical operator is limited to handling a row size greater than approximately 8 KB in size, and normally such plans are excluded from being run as a parallel plan. Due to a bug in the calculation of the row size when handling bit columns, the query is incorrectly allowed to run in parallel but overflows a buffer allocated for transferring the data between threads.