problem after uninstalling a custom module

hi,
I am working a product module.
To maintain the brands of the products , i had created a module - product brand master.
THen i created a relate fied to Product brand master - in product module through studio…

It was working fine. But was not able to see the prodcut brand master in Role management

Hence , i uninstalled the custom module of product brand master.

Now, i am not able to access the product module. It is giving an error.

I tried repairing and rebuilding the application.
I also , tried to empty the table of product master.

The product module is not working.

what can i do .

I have a backup of my previous database .