NM: Migration canceled due to fatal error (4312086)

Issue

All migrations are failing with the error:
Migration canceled due to fatal error (disk full, network lost, etc).

All the servers and migration workstations involved in the process all have free disk space, and there was no drop in network connectivity.

Solution

Confirm the workstation has at least 1 GB of free hard drive space.

Confirm there were no network connectivity issues.  Did you see a yellow warning in the tray stating Outlook lost it's connection?

If Migrating directly to Exchange, confirm the mail messages are below the Exchange maximum size limit or increase the size limit during the migration project.

From the Exchange Management Console
Organization config
   Hub Transport
      Global Settings tab
properties of Transport settings
max receive size - 10240 MB (unchecked)
max send size - 10240 MB (unchecked)

If migrating to a PST file as the destination, a Windows profile on the account was set to not allow the account to create .PST files, once this was modified migrations continued without error.

Also check the registry key. 

HK_CU\Software\Policies\Microsoft\Office\16.0\Outlook\PST\PSTDisableGrow=0

If this is set to 1, then the PST will not be able to grow.  See the value to 0 on the migration workstation.  

Office 365 has a MaxReceiveSize of (MaxReceiveSize : 150 MB which prevents messages larger than this from migrating fully.

Office 365 now supports larger email messages—up to 150 MB

If the global transport setting does seem to be taking affect, instead of migrating to the same mail file, try removing and recreating the mail file or use a  brand new user as a test. 

If the above steps do not resolve the problem, then perform the following steps on all migration workstations:

Make sure the notes client is shut down.

delete ~notes.lck
del Cache.NDK
del cluster.ncf
del JOBSCHED.NJF
del pid.nbf
del ~clipbrd.ncf
del btmail.box