This problem can be caused if a review type that has been used in programmes with Learners enrolled, is removed. 

We advise you to not remove any review types in the programme builder, as this will affect all reviews using this type, whether completed or not.

Please be advised that if the original review type is removed, but then re-added, this will not resolve the problem (as the link between the review and the review component will no longer be valid). 

The best way to resolve this situation if it should occur is is to review all review components in the Programme Builder and make sure that they refer to the correct review type and save the programme. 

You can test that this is working as required by picking one learner the programme has been applied to. You can then review all Learning Plan review components for that learner, and make sure that they refer to the correct review type. You can then sync to the remaining learners on the programme.