ARD 3.9: Authentication Failed

I have been experiencing this ARD Authentication Failed problem on some of my machines on the other end of a WAN link. It turns out there is a problem with the MTUs between the two endpoints of the WAN link (it was somehow set to 600). Setting the values to more normal and bigger values fixed this for me.

Here is my fix. Takes about 15 minutes once you have everything backed up and copied.

1. Quit Apple Remote Desktop
2. Navigate to the library folder within the user account you are running ARD.
3. Navigate to the Containers folder
4. Control Click the folder com.apple.RemoteDesktop and select compress from the menu. Your settings are now backed up
5. Move the com.apple.RemoteDesktop folder to the trash can, do not empty trash yet. Consider this file your second backup.
6. Navigate to the library > Preferences and select the com.apple.RemoteDesktop.plist file and select compress from the menu.
7. Move the com.apple.RemoteDesktop.plist to the trash.

If you launch ARD and you see all of your original setting you did the steps above while ARD was running.

1. Launch Apple Remote Desktop
2. Click the Agree button
3. Enter your workstation Admin password at the prompt.
4. Go with Defaults on Report Collection and click Done.

You will be back to the default setting of ARD, and it is now time to repopulate your settings. You should find that all of your clients are now bright Blue and responding, not just the 3.9 ARD clients.

My experience over the years of working with ARD is this app is testy. I approach every update or version change with the mindset that I am going to have to setup my ARD from scratch again. Many moons ago I used to tried many different fixes in an effort to avoid setting up ARD from scratch, but now know that is easier than living with the bugs.

If you have problems with this fix simply quit ARD, remove the aforementioned folder and plist file, then decompress the file and folder, launch ARD and you should be back to where you were.

Hope this helps.

I had the same problem. If you double click or right click and select "Get Info" on a computer that is listed in the Apple Remote Desktop main window a window pops up with four tabs. Select the "Attributes" tab and select edit. Try changing the "Login" to the short name if you remember it. Then select done and the try controlling the client computer again. It worked for me. There will probably be an update to fix this bug.

I too have had this issue and I to found that if you create a new user that ARD works. Sort of. Some of the features on ARD are not correct. I have been in communication with APPLE for 3 hours tonight. No solutions yet. But it is getting narrow down to the CLIENT side 3.9 Update that is causing the issues. Looks to be a Database issue. But not confirmed. No SUDO commands work none. I have tried them all. I have even trashed all Plist files and Container files for ARD on the client side and the issue comes back. The only solution as of right now is what you found out. Create a new ADMIN user for all of your machines. For me this is 44 Machines in different areas.. Its hard for me to make this happen quickly.. Good luck to you. As soon as I hear anything about the solution(s) I will pass it on RIGHT here in the apple community...

SCR, Capt.

I and 5 german Administrators have duplicated this issue on a total of 51 machines. So this is not a small issue. We are just the firsts to make note of it. I have been sending chats and emails to all my friends and IT professionals about this. So folks will delay their updates I hope.

SCR, Capt.

Would be interested to know if it holds for you. Worked for me perfectly on one admin machine, not on the second one. Then, after an hour or so, the first admin machine started losing connection to more and more of them as the day went on. I actually tried creating a new admin user on one client and changing log in to the new user but no affect.

Really incredible.

However, I found a solution that seems simpler than others I've seen posted here.

- Delete the computer from the "All Computers" list in ARD

- Select the "Add By Address..." command from the pop-up menu at the bottom of the ARD window

- Enter the IP address and the usual admin login credentials

- Get Info on the re-added client and click on the "Edit" button

- Copy the "Bonjour Name" to the "DNS Name" field

Following that operation, the client still says "Access Denied", but I am able to connect normally to the computer (I no longer get an "Authentication Failed" error).

Interestingly, some of the computers did not need the DNS Address to be edited; they got re-added with the correct name. And most stopped saying "Access Denied" and worked normally. Very inconsistent, no pattern that I could discern.

Also - I noticed I got an alert that says:

ARDAgent wants to use the "PrivateKeyStore-502" keychain. Please enter the keychain password.

But the password for that account does not work. Eventually if I cancel enough times it will go away, but I assume it's related to this nonsense.

Didn't work for me!

When I saw that ARD Agent wanted Keychain access, I reset the password in ARD in case this might be the issue. NOPE.

Interestingly, the only client that I can still connect to is an old 'student MacBook running 10.6.8 with vintage ARD client, and this is with the older client checkbox off.

Screen share still works, but only with in network client computers.

I am also having this issue.

Updated my all my client machines to 3.9 and have been unable to connect ever since.

I tried to update my personal machine to 3.9 as well. Didn't work.

Lastly, I tried the preferences trick (connect to less secure machines) with no luck either.

Same problem here.

If you connect with the "Connect to server" command in finder with vnc://address then it errors on first connection but then hit connect again and it authenticates fine. Connecting in ARD app with the short name credentials of the mac you are connecting to also works. If you are unsure of this then right click on the account in question and select Advanced Options in the Users & Groups control panel.

Clearly needs a 3.9.1 update!

I had this same problem and spent a good part of the day on the phone with Apple to no avail. I did figure out the problem though - in version 3.9 ARD is now looking for the client computers 'account name' instead of the 'user name'. For example, if your computers name is 'Bobs Imac', OS X creates an account name called 'bobsimac'. The later is what ARD is looking for to authenticate. Passwords are still the same.

Using Ewarrior99's logic in reverse, I changed the Login from the short name to the long name and now I am able to observe and control, but the Current Status of the machine in the list has "Access Denied." I use ARD with 10 separate client sites and this interestingly has happened to only one machine at one client.

I've got a studio/classroom with 24 iMacs, just upgraded to OS10.12.3 and ARD 3.9. The "Access Denied" issue is killing 3 classes.

I'm never sure when ARD asks for login is it should be from the admin computer account of the instructor station (that actually has the ARD application) or the student/client iMac's admin account (common all, different from instructor's). Is that a complication?

Could the LAN be an issue?