How To Fix TU214 - Advance payment not permissible on &1

SAP Error Message - Details

• Message type: E = Error

• Message class: TU - Billing/Scheduling/Budget Billing

• Message number: 214

• Message text: Advance payment not permissible on &1

What causes this issue?

Reasons:
A renewed agreement for advance payment on the specified date would
result in a combination of budget billing - advance payment - budget
billing - advance payment (BB-AP-BB-AP) or of AP-BB-AP. The maximum
possible combination is BB-AP-BB or AP-BB.
No modifiable due date exists after the specified date.
An unmodifiable due date exists after the specified date.

How to fix this error?

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

Error message extract from SAP system. Copyright SAP SE.