I have used Grocery CRUD several times, and this is a problem I have not run into before.
Even on the simple install, the update does not return a page. Instead, it returns a JSON success message. The problem seems to be that 'jquery.uniform.min.js' and 'jquery.uniform.config.js' are not loading. When I inspect the code, they are listed as loading after JQuery.
Again, this is 'out of the box' Grocery CRUD.
Has anyone else run into this, and do you have a solution?