NLP: Attribute ScalarNonlinearFunction is not supported by the model

The underlying cause is ANN: JuMP v1.15 is released

Some solvers have not been updated. So for SCIP and Alpine, you’ll need to use
@NLobjective instead of @objective.

AmplNLWriter with Couenne etc will work if you update your packages to AmplNLWriter v1.2.0.