Not enough budget available.

What causes this issue?

Not enough budget is available for control address (&V1&) &V2&.
An amount of &V3& is available, but &V4& is already reserved by other
users.

System Response

The process is stopped.

How to fix this error?

Transfer budget to the budget address used or use a different budget
address.

Error message extract from SAP system. Copyright SAP SE.