Activate real estate in controlling area &1 in &2

What causes this issue?

You have assigned to a real estate object, although Real Estate is not
active in controlling area &V1& in fiscal year &V2&.

System Response

You can only assign real estate objects if Real Estate Management is
active in the controlling area.

How to fix this error?

Enter another CO account assignment object or
Activate the Real Estate Management component in controlling area &V1&,
fiscal year &V2&.
To do so, see the "General Controlling" section of the Implementation
Guide (IMG) and choose "Organization" ->
<DS:SIMG.SIMG_CFMENUORK3OKKP>"Maintain Controlling Area"</>
If you are using the "real estate object" field to archive your own
information for a posting in the SAP system, you should make use of the
enhancement to the account assignment block, which offers you
user-defined fields.
To do so, in the "Special Purpose Ledger" section of the Implementation
Guide (IMG) choose "Basic Settings" -> <DS:SIMG.SIMG_XXAK_OXK3>"Maintain
Coding Block"</>.

Error message extract from SAP system. Copyright SAP SE.