Xcode Command-Slash Shortcut to Comment Only Works Sometimes

For an Xcode 8, solution is

sudo /usr/libexec/xpccachectl

and restart your computer.

Hit ⌘+] once and then ⌘+/ will start working again.

You can hit ⌘+[ to undo the indentation effect.

Update:

Please note- This solution was provided prior to Xcode 8 launch so it may not work for everyone. If you are still facing problem, kindly refer to @CryingHippo's answer instead of downvoting.

I have done this numerous times with Xcode 8. Latest being Xcode 10.1 where I would just quit Xcode and go to Applications and rename Xcode to something else, e.g. Xcode 2, launch it, quit again and rename back. It starts working after that. No Mac restart or Terminal commands required.

It still works as of Xcode 10.1. I cannot believe Apple still hasn't fixed it properly.

None of the above solutions worked for me with Xcode 8.0 (final). If you also have Xcode 8.1 beta installed like I do, try this: simply rename /Applications/Xcode-beta.app to something else, then restart Xcode 8. Oddly enough, that did the trick.

Oscahie's answer actually works for non-beta versions of Xcode as well. Here are the steps to follow, based on Sam's comment:

Close Xcode In the Application folder, rename Xcode.app (or similar) to Xcode2.app. You might need to type in your password. Open Xcode, then close it. Rename Xcode2.app back to what it was before. (Optional) Spend 5 minutes wondering why this worked.

No need to reboot!

I didn't have to do any of the above. A simple reboot fixed it.

A simple workaround works good for me with following steps:

Comment any line i.e. simply add "//" in front of a line. Press Command + "/" and it starts working.

It might help someone.

In my code I had this sequence:
/*" BLABLA MY COMMENTS */
All the code under this was not "commentable".

Removed the " and it was ok !

Hope it helps!

I just had the same issue after setting up a new Mac with Xcode 10.1 using the German keyboard layout.

The solution was to disable the Keyboard shortcut in system settings for the help menu.

System settings > Keyboard > Shortcuts > App shortcuts.

There was a shortcut for all apps to show the help menu. If you have that, click the checkbox to disable it

https://i.stack.imgur.com/Eplkx.png

I am using Xcode 8.1 (not beta) and I had the same problem, not able to cmd+\ to comment. Restart Xcode not working for me but RESTART my Mac SOLVED the problem without a need to remove cache.

I had this problem in Xcode 8.0. Even though I already move Xcode 8.1-beta somewhere else (It's at Application/Xcode otherversions/Xcode 8.1-beta.app). I have to delete it to the trash, restart Xcode 8.0, and cmd+/ somehow works again.

Just quit xcode completely and restart. Worked for xcode 8.2

I was also facing this issue, when having multiple Xcode installed.

In which Xcode version you are you facing this problem, to solve this, the Xcode should be in the Application Folder. If it resides in the subfolder than move it to the Application folder directly.

I found a pattern where toggle comments do not work. In fact, uncomment works, but comment don't, from keyboard as well as from the Editor menu. This happens in a specific file, suggesting there is something in text that prevents from working. I tested on XCode 10.1ß and on XCode10.2, on different machines.

Text before this line can be commented, text after cannot (I kept text exactly as is)

let alert = UIAlertController(title: "" /*"Teste texte"*/, message: "Love\nWe'll recommend more for you" /* Entrez des chiffres"*/, preferredStyle: .alert)  

It appears that the /* … */ inside the UIAlertController() is the cause. If I suppress both comments inside, everything works OK.

I filed a bug report. # 49907361

Nothing above worked, even after trying multiple times.

Just reinstalled new xcode using AppStore app, previously I installed xcode after downloading from developer.apple.com/downloads. that is .xip file

Wait for new update and install.

Another reason may be that xcode isn't in Application directory.