Problem

You notice the following error message in your migration logs :
Start() Error for user@company.com : Unable to connect to the target : Unable to login to ‘user@company.com’ Cannot contact site at the specified URL https://yourcompany-my.sharepoint.com/personal/user_company_com.

Cause 1 : During File Migration

This is because the OneDrive account for this user has not been provisioned.
To check if the OneDrive exists, as administrator of your Office 365 domain, go to this URL:

https://-my.sharepoint.com/personal/user_company_com/_layouts/15/onedrive.aspx

Replace -my.sharepoint.com with your company name
Replace user_company_com by the user’s email of the OneDrive that you want to check (don’t forget to replace ‘.’, ‘@’, … by ‘_’ in the URL).
If you get “Page not Found”, the OneDrive has not been provisioned.

Resolution

To solve the problem, provision the OneDrive profile either by asking the user to log on to his OneDrive or by running the preprocessing task on this user.

 

Cause 2 : During Site migration

The site you are trying to connect does not exist in SharePoint Central administration.

Resolution

To solve the issue, create the site collection on SharePoint Central administration and relaunch the migration once the site is created.

 

Cause 3 : During Site migration

The Target Site Collection field in the sitelist  is not correctly filled. The Target Site Collection must be filled in with the site collection’s relative URL.

Resolution

Put the right site collection relative URL in the field Target Site Collection

For example, if the site collection URL is: https://company.sharepoint.com/sites/test, the Target site Collection should be sites/test

Note: please especially check if there is no any spaces characters in your URL string.