While copying files, ShareGate Migrate displays the following message:

Unable to copy your file. This file type is blocked by SharePoint due to security risks.

This message is displayed when the source or destination SharePoint server blocks the copy of a file due to its file extension. SharePoint has a default list of file extensions that cannot be uploaded because that file type may pose a security risk to your SharePoint environment.

While it is possible to unblock file extensions from the SharePoint central admin, this will not affect the blocked file extensions list in ShareGate Migrate.

For more information on SharePoint's blocked file extensions, see the Microsoft article Types of files that cannot be added to a list or library.