Currency in FM area & must not be changed

What causes this issue?

You must not change the currency in FM area &V1& if:

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

Cash Budget Management, Project Cash Management or Funds Management has
been activated for one or more of the company codes assigned to FM area
&V1&
FM area &V1& already contains actual data in one of the components
mentioned.
Budget Values already exist in FM area.

System Response

How to fix this error?

Error message extract from SAP system. Copyright SAP SE.