Magento Version 2.4.6-p6
Uberthemes MegaMenu version 1.2.8
When importing categories into the mega menu, I can see a javascript error in the console. This seems to be related to deprecated callbacks in the ub-import-categories.js file. It is recommended to replace the .success and .complete callbacks with .done and .always.
At this moment in time, without overriding this javascript file, this functionality is broken.
