Power Automate: Lookup column throws error 'data type is not supported'

Issue:

A flow was created to run whenever a new item was created or edited. The flow did not run at all and instead advised that there is an issue with the flow’s trigger.

Trigger image

Clicking on ‘Fix the trigger’ displays the flow with an error on the trigger.

The following error message is displayed:

{
  "status": 400,
  "message": "The required field \"Related risk(s)\" data type is not supported\r\nclientRequestId: 7e29a495-ddab-4c6c-8af7-0b73ca51381a\r\nserviceRequestId: 7e29a495-ddab-4c6c-8af7-0b73ca51381a"
}

Resolution

The lookup column value was using the Title (linked to item) field. Changing this to normal Title column resolved the issue.

The error message remained in place for a while but workflows started running correctly.