Old fiscal year posted to again by document &

What causes this issue?

You are changing the amount in a document whose preceding document is
&V1&. Document &V1& was not carried over in the commitments carryforward
for the fiscal year change because it was reduced to zero in the old
year.
The change you are making now leads to a new commitment amount in the
old fiscal year, caused by document &V1&.

How to fix this error?

Check whether the change is really necessary. If it is, you must run the
commitments carryforward for the fiscal year change again.

Error message extract from SAP system. Copyright SAP SE.