G/L account &1 is a balance sheet account

What causes this issue?

G/L account &V1& is defined in FI as a balance sheet account.

System Response

Balance sheet accounts <ZH>cannot</> be created as cost elements in
cost accounting, <ZH>except for</>:
Asset reconciliation accounts
Material stock accounts for valuated sales order stock for
<DS:GLOS.3526BEAAAFAB52B9E10000009B38F974>sales orders</> or
<DS:GLOS.3526C033AFAB52B9E10000009B38F974>projects</>.

Error message extract from SAP system. Copyright SAP SE.