Symptoms
When copying, ShareGate Migrate displays one of the following error messages:
The list field that the lookup field 'My Lookup Field' references cannot be found at the source.
โThe referenced list column 'The referenced field' was not found in the source list.
Error code
ST-068-007
ST-069-007
ST-156-007
Details
This error can happen in one of the following scenarios:
When copying a lookup site column.
When copying a list/library that contains a lookup column.
This error means that the lookup column is corrupted because it refers to a list column that no longer exists. For this reason, ShareGate Migrate cannot copy the column or set a value in it.
In most cases, when going in the lookup column settings, SharePoint will display "Title" in the "In this column" drop-down, because this is the fallback value that SharePoint uses when the column reference is broken.
Solution
From the source site in SharePoint: