Formula & uses operands with incompatible dimensions

What causes this issue?

The operands of formula &V1& do not have the same currency or unit
dimension. This could mean for example that the quantities and amounts,
or amounts and ratios, or the exponents of the currency or unit
dimension are different.
Examples of wrong formulas:
Amount + Quantity (for example $ + kg)
Amount * Amount + Amount (for example $? + $)
When using operator 'IF', the dimension of the condition operand is not
relevant and is not checked.

How to fix this error?

Check your definition.
If the formula still makes sense, you can hide the dimensionality with
operator 'NODIM'. The system then treats the number as a dimensionless
number.

Error message extract from SAP system. Copyright SAP SE.