If you have this error on the migration role ( SMS_MIGRATION_MANAGER) :
SMS Executive detected that this component stopped unexpectedly.
Possible cause: The component is experiencing a severe problem that caused it to stop unexpectedly.
Solution: Refer to your ConfigMgr Documentation or the Microsoft Knowledge Base for further troubleshooting information.
Download this DLL microsoft.configurationmanagement.migrationmanager.dll and copy and past to the
For download DLL, click HERE
For resolve,you do:
Open Command prompt and type
c:\Windows\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe "\Program Files\Microsoft Configuration Manager\bin\X64\microsoft.configurationmanagement.migrationmanager.dll" /codebase
Attention, verify the path if his correct before launch command...