Knowledge Base

How to troubleshoot being unable to match mailboxes for migration

This article is obsolete and may relate only to older versions of our software.


You are unable to perform mailboxes matching when configuring a migration job in CodeTwo Office 365 Migration. You get the following error message:

The type initializer for 'Microsoft.Online.Administration.Automation.ConnectMsolervice' threw an exception.


This issue occurs because the Microsoft Online Services Sign-In Assistant is not installed on your machine. Keep in mind that the Microsoft Online Services Sign-In Assistant is one of the components that is required for CodeTwo Office 365 Migration to work properly and is installed together with our migration software. However, once you uninstall the sign-in assistant from your machine, you need to install it again manually.

To fix the problem described in this article, follow these steps:

  1. Close CodeTwo Office 365 Migration.
  2. Download and install Microsoft Online Services Sign-In Assistant for IT Professionals RTW.
  3. Run CodeTwo Office 365 Migration again.

You should now be able to run automatic mailbox matching.


The Microsoft Online Services Sign-In Assistant is no longer required by CodeTwo Office 365 Migration version 3.2.x and higher. Click here to download the newest version of the software.


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