Changing the active PAP solution may lead to inconsistencies

What causes this issue?

Causes for the message could be:

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

You are choosing the PAP Refactored solution to be the active PAP
solution.
In this case all PAPs created with the previously existent solution
should be closed (no PAP should exist in status ?in preparation?,
?request approval? or ?approved with errors?).
You are reverting to the old PAP solution.
In case you already have PAPs created with new solution, transaction
PFM_12FIBI05 should no longer be used due to risk of inconsistencies in
balances (CRR, Own Revenues, Monthly Budget).

Error message extract from SAP system. Copyright SAP SE.