I\'m running a TFS -> VSTS migration using OpsHub Visual Studio Online Migration utility.
Version-1.0
OpsHub Integration Manager Framewor
Try clearing the Team Foundation cache on your migration computer. To do so, follow these instructions:
We had the same issue earlier today, which completely blocked our migration for 3 hours until I did this.
If this is happening to you daily, then you might want to do this each afternoon (until your migration is complete).