Thanks for your response.
The tag name is correct. I created another custom field with the same list and settings, and the above code works
As a test, I then changed the tag of the problematic custom field, ran the code and that didn't work. I even changed the tag to match the newly created custom field (after renaming it) and that also didn't work.
Could a setting cause the value not to be changed with custom lists?
Edit:
I exported my custom fields and opened the file with Notepad++, the custom field I'm having problems with has:
I removed that, saved the file and imported it back into Ant Movie Catalog and the script ran fine. I then found that setting can be changed
when opening the scripting window in the "Modifiable fields" section. I had unchecked it years ago
