During the migration process, you see that the Lotus Notes client crashes on the Migrator for Notes to Exchange (MNE) console. This may cause the MNE application to crash as well.
The Notes Client crashes on the MNE migration server may occur randomly, using any version of MNE.
It is possible that the Lotus Notes client may not be at the latest FixPack and cause intermittent client crashes.
Refer to the IBM Fix Central website to find more about these product defects
https://www-945.ibm.com/support/fixcentral/
Note: If there are random crashes while running Notes Client 8.5.3, patch the Lotus Notes client to the most recent FixPack available.