Steps to reproduce:
1. Open any change request record having conflict detected.
2. Go to the inspect element and click on the console.
3. An error with the red mark will come saying.
"Uncaught TypeError: Cannot read property 'hide' of null
at updateWarningBoxAndConflictButton (ChangeRequestConflictUtils.jsdbx?v=08-10-2020_1624&c=31_853:190)"
The issue is occurring as the Ui marco "change_request_conflict_progress" was customized.
// Get references to the two gui widgets you intend to enable/disable
var warningBox = $('conflictDetectionStatus');
var checkConflictsButton = $('conflict_action_run');
<div id="conflictDetectionStatus" class="outputmsg outputmsg_warning notification notification-warning" style="display: none">
The Ui script : ChangeRequestConflictUtils was calling function updateWarningBoxAndConflictButton
Where it was fetching conflictDetectionStatus parameter from the above Ui macro which was returning null causing the error in the console.
Reverting the same to OOB, resolved the issue