{num}
I can confirm that lately I have not been able to use <C-^> as well, using the latest stable version
Thanks for the report, @meijieru and @badosu! This seems to be related to the keyboard layout - I'm wondering if it is being picked up as a dead key.
Would it be possible to grab the logs from the console when you execute that keystroke?
Control+Shift+P -> Open DevToolsOni.log.enableDebugLogging()
This can help narrow down how the key press is being resolved / what's going wrong.
In addition, knowing what the keyboard-layout module sees as the current language, would be helpful, too:

You can check that by running the require("keyboard-layout").getCurrentKeyboardLanguage()
Thanks the report & your help!
@bryphe Sorry, I am not familiar with node js, so where should I enter this command Oni.log.enableDebugLogging()? I try it within console, but it says this is undefined.
Anything new?
What version of Oni are you currently using?
I'm able to use <Ctrl+^> on the latest build, so its possible its working now.
If that doesn't work, the place you'd enter Oni.log.enableDebugLogging() and require("keyboard-layout").getCurrentKeyboardLanguage() is in the Chrome dev tools. You access that with <Ctrl+Shift+P> and typing Dev tools.
@CrossR I am using the latest stable (0.3.1) and this issue persists. This is the output on a normal Oni installation:
< require("keyboard-layout").getCurrentKeyboardLanguage()
> "us [0]"
Hm, mine works on US and UK keyboards, but I've only tested on Windows.
What is the output of the verbose log?
I get the following for 3<Ctrl+^>.

Ok, it seems that <Ctrl-^> is working, but the help text makes it seem like <Ctrl-6> should work as well (that's how I used it previously).
I am fine using <Ctrl-^> if that's not a bug.
*CTRL-^* *CTRL-6*
CTRL-^ Edit the alternate file. Mostly the alternate file is
the previously edited file. This is a quick way to
toggle between two files. It is equivalent to ":e #",
except that it also works when there is no file name.
If the 'autowrite' or 'autowriteall' option is on and
the buffer was changed, write it.
Mostly the ^ character is positioned on the 6 key,
pressing CTRL and 6 then gets you what we call CTRL-^.
But on some non-US keyboards CTRL-^ is produced in
another way.
This is my <Ctrl-6> output:

I'm a bit of a buffers newbie, but the behaviour for me (again Windows only currently, I should probably test on my Arch box) is the same behaviour as in nvim-qt and nvim in the terminal.
For other platforms though, we could have a keyboard capture issue, but it looks as if <Ctrl-6> is being picked up correctly.
@CrossR Makes sense, I've been using Oni for a while so maybe my memory on my previous workflow is not as good (which works with <C-^> now).
The pending issue now is for @meijieru to check if it's working for him and to provide his debug details.
@badosu
So is it possible to enable < c - 6 > as well?
@meijieru It is working for me at the moment without any configuration, can you confirm if you still can't use it in Oni on the last stable release (0.3.1)?
@badosu Github conceal the
Looks like this might have been "sorted" over in #2002.
We could use this ticket to track adding a default keybind, if we think its needed.
Though we could just end up adding a keybind that causes people issues, so we'd have to be careful to make sure its easily disabled....May just make more sense to add documentation around it instead?
@CrossR Yes, per https://github.com/onivim/oni/issues/2002#issuecomment-377691048 it seems it's safe to assume <C-^> is the canonical keybinding.