SuiteCRM 7.12 Admin Dropdown Editor unacessible


I was using SuiteCRM 7.12.4 and noted going from the Admin page Dropdown Editor could not be accessed.
When clicking on " Dropdown Editor" on Admin page, the only loaded page is the common page for “Studio/Module Builder/Dropdown Editor” you reach when clicking on the Home icon from Studio.
Thinking of a bug I upgraded to the 7.12.5 but the issue remains.

I started digging in and found out the issue lays down in the URL generated when on the Admin page clicking on the “Dropdown Editor” link.
It is of the form:
when it should be of

To validate this I entered in my web browser the latter URL and it worked.
Where in the SuiteCRM file structure is generated the URL of the Admin page for “Dropdown Editor”?

Looking forward to your help and support.