Using ArcGIS Pro 3.1.2 with Enterprise Portal 11.0
Is it not possible to update multiple fields using a Batch calculation?
I'm attempting to create a very basic batch calculation rule as part of a test, but it keeps failing. The same code when used as an Immediate calculation works:
return {
"result" : {
"attributes" : {
"UNIT_ID" : $feature.UNIT_ID,
"SITE_ID" : 'Location Test',
"SITE_NAME" : 'Location Test'
}}}
When I run it, I receive this error:

The server log for the error reads:

If I change the rule to "return $feature.UNIT_ID" it works, so I know the value is compatible.