Request to js/admin_menu/cache/% generates page not found

This means that the menu system on your site does not (yet) know of this (new) path. Just hit the "Flush all caches" button/link.

Got same issue on my system. The problem was that my caching server is automatically passing /js/ path to another location and this request is not handled by Drupal. After creating ignore rule for /js/admin_menu no more errors. But I think /js/ path is not a good for module urls. Better to use <module name> prefix for module paths to avoid conflicts

Just started using Drupal and experiencing the same problem. Trying to edit nodes etc takes me to blank pages. In log report js/admin_menu/cache/51359c9bb999d1d5d0ec58a781cce244 page not found. Emptying cache did not solve the problem. How do I create ignore rule for /js/admin_menu? I'm very much on the lower slopes of the learning curve and this hurdle is not helping as the admin menu is practically unusable at present.

I have same problem, I clear all cache and only get a white blank bar.

I had same issue, The problem for me was because apache has not rewrite module enabled. >)

Well, i know it's late but.. #7 definately fixed it for me. I feel stupid :')

Same on 7.x version. After updating to OSX Sierra, had to re-enable mod_rewrite on my local environment.

#7 fixed for me the error - I had to enable apache rewrite module after reinstall of Ubuntu 16.04 due to a harddisk crash. Thanks :)