There are a couple of scenarios where the IPP would fail and throw an error that is seen in the above screenshot

Scenario:1 If the custodian doesn’t have a data source at all or has a different data source than what is specified in the Legal hold’s preservation data source.

Solution: Add the Data source to the custodian and ensure the right Datasource type is selected in the preservation data source field. 

Scenario:2Adding the preservation data source after issuing the legal hold

Solution: If you have added the Preservation data source after issuing the legal hold, you should re-issue the Legal hold to one of the custodians who have the same Datasource type to reinitiate the IPP.