BitTitan Migration to Office 365 – “The XML document ended unexpectedly”

While performing a migration from Exchange 2007 to Office 365 using BitTitan Migration Wiz, a strange error was generated for each mailbox that was being migrated. The error message is cryptic at best – “The XML document ended unexpectedly”. That error looked like this in the wizard:

There are quite a few articles, blog posts, etc. out there on this issue:
BitTitan Support Doc
Microsoft Forum Post
However, none of these solve the problem. The solution in the end was to fix Exchange Performance counters. This solution was found due to errors located in the Application log, which led to a Microsoft Support Document

Add-Pssnapin Microsoft.Exchange.Management.PowerShell.Setup
New-PerfCounters –definitionfilename “C:\Program Files\Microsoft\Exchange Server\V15\Setup\Perf\GlsPerformanceCounters.xml

After that, the migrations with BitTitan were able to get past this error.