Test if a Time field value changed in flow decision... causing exception

Question

I ran into an issue with a flow who stopped with an error, giving no more details than :

UNKNOWN_EXCEPTION: An unexpected error occurred. Please include this ErrorId if you contact support: 2033648372-927914 (81955499).

The log showed no error at all, just endend after a decision. I could isolate and reproduce the issue:

• I created a SObject Test__c with a field named TimeField__c, and an instance of it, and then created a flow with this decision:

Then I debugged the flow, not even changing the time, and I got this error : Value of class com.force.swag.soap.Time is not a ValueType: STRING

It's obviously a Salesforce bug, I should be able to check if a time field changed. Using Record.Timefield__c != Record_Prior.Timefield__c or using a formula to compare values didn't help, the bug's still here.

I found however a workaround that I'll share in an answer.

Answer 1

As a workaround, I created a formula (text type) to reference the time field, simply TEXT(TimeField__c)

and then updated my decision to reference the formula instead of the Time field.

The bug is no longer active and the comparison works since it's not directly on a time field anymore.