Chrome Version: (copy from chrome://version) 64.0.3282.186 (Official Build) (64-bit) 
OS: (e.g. Win7, OSX 10.9.5, etc...) Win10 Version 1709 (build 16299.248)

What steps will reproduce the problem?
(1)Drag local .crx into the chrome://extensions tab while in developer mode 
(2)Extension will show up in the list but will not work
(3)

What is the expected result? In developer mode - the extension should work to be tested locally.

What happens instead?

Please use labels and text to provide additional information.

See the following video that demonstrates the issue:  https://youtu.be/9lXlwXjPKZ8