I'm not sure if this is specific to FNEI, but since upgrading from 0.16.16 to 0.16.17 I'm unable to open the FNEI window with the configured shortcut. I've tried the default Control+E as well as changing it to Shift+Control+E and Control+R.

This is under macOS.

Thanks for your feedback, I will check this out later and describe the result here.

Just to confirm, tested under 0.16.18 and I experience the same symptoms.

It's strange, I tried open the GUI on my computer, I have all the normal open. I checked under windows OS. Try the following:
1) check whether there is this mod and whether it is activated in the game mods
2) create a new game and try to open the gui
3) try to turn off the mod, restart the game, and then turn on the mod again.
If this does not help you write about it on the forum.

I've tried disabling/loading/enabling/reloading my save and with a new game, same result. I'm not sure if it's limited to FNEI as other mods appear to have similar problems.

I'm beginning to wonder if it's not related to this from the 0.16.17 changelog.

• Fixed un-setting controls wouldn't work correctly for key bindings with default modifiers. (56659)

Also just found this: https://forums.factorio.com/viewtopic.php?f=7&t=57013

0.16.19 has fixed this issue.