I'm trying to migrate a MySQL database to SQL Server using the SQL Server Migration Assistant for MySQL. Converting the schema and synchronizing with SQL Server works fine.

However, after clicking the Migrate Data button, SSMA crashes after a few seconds (SSMA has stopped working). What might be the cause of this problem?

2 Answers 2


One more thing that helped me in addition to setting affinity to Core 0 only:

SSMA stopped crashing after I set Parallel Data Migration Thread Count to 1. You can find it in Tools > Project settings > Genaral > Migration (in the left pane) > Parallel Data Migration. Set Parallel data migration mode to Custom and then Thread count to 1.

My current version is 7.0.0, MySQL ODBC Driver version is 5.3.6.

  • Interesting, didn't found this option earlier. Oct 28, 2016 at 6:26

On some certain conditions, SSMA seems to cause problems when using it on a multi-core machine.

I opened the Task Manager and set SSMA's processor affinity to Core 0 only. This fixed the crash and I was able to migrate the whole database.

  • This fix also applies to the SSMA for Access (confirmed on version 18.8, the latest version as of today)
    – Mike
    Apr 12, 2021 at 5:18

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