No suitable G/L ledger found for CO

What causes this issue?

There is no G/L ledger that has the same fiscal year variant for all
company codes that are assigned to a controlling area.

System Response

This means that the system can't determine a G/L ledger which could act
as ledger for CO data for all company codes.
Background:
In SAP S/4HANA Finance FI and CO share the same persistence for storing
postings: CO data is stored in a G/L ledger. The customizing migration
program evaluates the ledger settings to find a G/L ledger that can be
used for this purpose.
For some reports it's necessary that this ledger is the same for all
company codes.

How to fix this error?

You have the following options:
Either adjust the fiscal year variants of the controlling area, or
Define a ledger with a suitable fiscal year variant for all company
codes; then assign the CO version 000 manually to this ledger for all
company codes.

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.