Account assignment adopted from document &1 &2

What causes this issue?

You are editing a document and reference the current line to the
<DS:GLOS.3526BB77AFAB52B9E10000009B38F974>earmarked funds</> &V1&, item
&V2&.

System Response

The system adopts the account assignment from the earmarked funds as
the default values for the account assignment fields in the current
document line, overwriting the account assignments entered there.

How to fix this error?

In the standard system we deliver, the referencing document (the one
you are currently working in) must have the same account assignment as
the earmarked funds being referenced.
If you want to enter a different account assignment from the one in the
account assignment referenced, you must set the
<DS:DE.MRACCHANG>Account assignment changeable</> indicator in
earmarked funds &V1&, item &V2&.

Error message extract from SAP system. Copyright SAP SE.