Hi there,
My User-Defined Fields is no longer working for the form AR203500. It previously worked fine.

The look-up is returning the relevant values, yet when one of them is selected, the above error occurs.

Here is the associated attribute:

(Out of curiosity, I created a new attribute to test this using a different DAC Schema, which did not return an error, below is the attribute that is working OK as an user defined field):

Any ideas where I should be looking to resolve this error?