Informative error message when using scale parameter values without required metadata

[Max Ghenis]

When using scale parameters with amount/threshold/rate fields, and omitting the required type metadata field, and calling it via calc, the error message gives something like "int isn't callable". It would be helpful for the error message to say that it's not a scale parameter.

[Mahdi Ben Jelloul]

Hi @MaxGhenis. Could you provide a reproductible minimal example so I can try to fix this. Thanks !