Attribute Rules can't be saved

[HanZheng]

Hello,

I created a immediate calculation rule to calculate the length of polyline when the insert/update action occurred. I made sure I checked syntax when enter the Arcade codes, but when I tried to save rule, the rule row turned red without telling what's wrong. 

Does anyone have idea what's wrong with this rule? The targeted field "Length_" has data type of "float". The polyline feature class uses WGS1984 (WKID 4326) and probably because of that, the default shape_length return incorrect shape length numbers. That's why I decided to set up a new column. I tried to use field calculator just to make sure calculate geometry worked under this spatial reference.

[DanPatterson]

what about length geodesic

Geometry functions | ArcGIS Arcade | ArcGIS Developers

[JohannesLindner · Accepted solution]

If you hover over the red square, it should tell you what's wrong.

Common reasons you can't save a rule:

• You forgot to add GlobalIDs to the feature class
• You forgot to set a trigger event
• Error in your script
• You're editing the feature class (though that will deactivate the save button, not show the red square)

[HanZheng]

Thanks. I didn't realize that's the way to find error message. Global ID was the issue for my case.