There is an inconsistency in the availability of rental object &1

What causes this issue?

The availability entered for rental object &V1& is not compatible with
that of its higher-level object (building/land or business entity). The
higher-level object has the status "not available" at a point in time
that does not apply for the rental object.
This error occurs when the availability status of an object was changed
without the status of the lower-level objects being modified.

System Response

You can change error handling in the <DS:SIMG.SIMG_CFMENUORK3OBA5>Change
Message Control</> IMG activity.
If the message is output as a warning, then you can continue with the
migration. However, this means that problems could arise in the check of
the generated cash flow.
If the message is suppressed, then the system skips the check (which is
otherwise very demanding on system performance). You should only use
this option if preceding checks here did not find any errors.

How to fix this error?

Check and correct the availability status of the affected objects using
the appropriate master data dialog transactions.

Procedure for System Administrators

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.