Yoou are migrating an archive between Office 365 tenants and you’re hitting the following error:

Fatal error during migration process: Test Archive Connection Failed : The specified folder could not be found in the store

Problem

Your archive migration runs into the following error and stops:

“Fatal error during migration process: Test Archive Connection Failed : The specified folder could not be found in the store.”

Cause

The user’s archive is disabled on the target Office 365 tenant.

Resolution

Turn on the user’s archive on the target Office 365 tenant.

See this Microsoft’s technet article for more information : https://technet.microsoft.com/en-us/library/jj984357(v=exchg.150).aspx