exchange – 2010 to 2016 Public Folder Migration – Error: MigrationMRSPermanentException

Migrating 60gb of 2010 public folders to 2016 (on premise, 9 PF mailboxes). Mailboxes 2-9 show as “Synced” and mailbox 1 shows “Failed” with this error:

Data migrated: 8.504 GB ‎(9,130,858,171 bytes)‎ Migration rate: 0 B
‎(0 bytes)‎ Error: MigrationMRSPermanentException: Error: Property
expression “1234 Folder name” isn‎’t valid. Valid values are: Strings
formed with characters from A to Z ‎(uppercase or lowercase)‎, digits
from 0 to 9, !, #, $, %, &, ‎’, , +, -, /, =, ?, ^, _, `, {, |, } or
~. One or more periods may be embedded in an alias, but each period
should be preceded and followed by at least one of the other
characters. Unicode characters from U+00A1 to U+00FF are also valid in
an alias, but they will be mapped to a best-fit US-ASCII string in the
e-mail address, which is generated from such an alias.

I have a pst backup of that folder so I have deleted it from the 2010 server.

How do I restart the migration so I can get to the 95% complete point?

I’m on Step 5 of this guide: https://docs.microsoft.com/en-us/Exchange/collaboration/public-folders/batch-migration-from-previous-versions?redirectedfrom=MSDN&view=exchserver-2016#step-1-download-the-migration-scripts

I tried this command ( Get-PublicFolderMigrationRequest | Resume-PublicFolderMigrationRequest ) but it didn’t seem to do anything.