After upgrade from CE 2.1.1 > 2.1.5 category select in product admin is blank?

Question

I've just upgraded Magento from 2.1.1 to 2.1.5 (via composer) and all went well except for 1 bug..

If I go to admin > products > catalog and pick any product from the catalogue to open the edit screen the "Categories" select box is blank?

I have no idea on where to start debugging this as there are no console errors or anything in the logs (Magento or PHP error logs)

I've tried disabling 3rd party modules with no effect?

Answer 1

Just to follow up - I've managed to fix this by disabling JS merging and JS Minify in the Magento settings... It's not a "fix" but more of a workaround (just in case anyone else has the same issue)