Problem

During migration of Google Groups to an Office 365 Unified group, you have noticed following error:
“Fatal error during migration process: Initialization of Office 365 Unified [Name of group] Group Failed : Processing data from remote server outlook.office365.com failed with the following error message: [description] Fail to create a runspace because you have exceeded the maximum number of connections allowed : 3 for the policy party : MaxConcurrency. Please close existing runspace and try again.

Cause

To create a new Office 365 group or add members to the Office 365 group the platform connects to your target Office 365 via PowerShell. If you start several migrations, there are several connections that can be opened at the same time. Microsoft allows to have only 3 concurrent connections per account. If this number is exceeded, you hit the indicated error.

Resolution

Try to restart your migration later or configure another target connector with the second admin account.