You must remove the read-only lock from your source site collection and columns before running a migration with ShareGate Migrate.

ShareGate uses multiple APIs to process SharePoint migrations. Read-only locks can cause errors and prevent data from copying properly.

If your source site collection or columns are ReadOnly, follow Microsoft's instructions here to change them to the unlocked lock state.

When your migration's complete, you can re-activate the read-only lock(s) if desired.