TypeError Message on 'Save Merge' Search Source

[Jesse20]

Our team recently upgraded to the Rome release and while going through skips, I noticed that if you you attempted to perform the 'Save Merge' on any records relating to a Search Source (e.g. Service Portal, Knowledge Portal, etc.) that this error would display regardless of whether or not the local record was modified (literally no change, just open the record and hit Save Merge):

Error MessageonSubmit script error: TypeError: widget.getAttribute is not a function:

function default_on_submit() {
if (!g_form)
return true;
return g_form.onSubmit();
}

I wasted at least an hour or two going through potentially conflicting scripts within UI Actions, UI Policies, Client Scripts, etc, as well as, digging through the Known Problems, Release Notes, this forum, and of course Google... but found nothing. HI Support gave a proposed solution, but at the time it's not openly accessible, not easily found, and formatted incorrectly. It could however be fixed by the time you read this post, but if not, then I figured that I'd share to help anyone else that run across this issue. 

-------------------

We are moving your case to Solution Proposed as we believe the information provided below will resolve your issue. If you have any questions or need anything else related to this Case kindly contact us or update the case and we will be happy to assist you further. If this resolves your issue, please consider closing the Case by clicking on Accept Solution.

Reason: This issue has been identified in a known PRB:
PRB1532168 - When merging customization using merge_form_upgrade.do "Save Merge" UI Action is displaying TypeError message "onSubmit script error: TypeError:"

Issue: Any attempt to resolve conflicts through the 'Save Merge' option gives the error:
function default_on_submit() {
if (!g_form)
return true;
return g_form.onSubmit();
}

Most Probable Cause: identified as a problem PRB1532168, will be release in San Diego Release

Solution Proposed: The workaround for this issue is to manually update the record.

Next Steps: We have attached the known PRB PRB1532168 to this case.