I have a REST query that looks like this
That works fine. But when I try to pull another field from the lookup list, I get an error. This query:
The query to field 'LookupField/CustomField' is not valid.
I should point out that if I try to pull in a standard field such as
LookupField/Created it works fine. It's only when I try to select a custom field that I get this error. Is that a limitation of the SharePoint API?