I have a site that I upgraded from Joomla 2.5 to 3.10.12. The previous site is using Multicategories v1.0.4 component, it doesn't work on Joomla 3.10 and there is no update from the Author so I tried to upgrade the component manually.
I got it to work until the Control Panel tab: http://www.domain.local/administrator/index.php?option=com_multicategories
But when I click on Categories, I get the error below: http://www.domain.local/administrator/index.php?option=com_multicategories&view=categories&extension=com_multicategories
500 Joomla\CMS\Form\Form::getInstance() could not load file
File directory: administrator/components/com _multicategories
I tried searching for solutions online but couldn't find much and it does work on me.
Any advice on how I can fix this or what is causing the error? thanks