On my client PC I'm running Windows 10 and I have installed XMing and Xming Fonts.

I am running Putty and I have configured it to enable X11 Forwarding. I have tried leaving the X display location blank (as default) and also with the value :0.0.

On my server I'm running Ubuntu on AWS. I edited the /etc/ssh/ssh_config file to include the following two lines:

ForwardX11 yes
ForwardX11Trusted yes

I also installed xauth using sudo apt-get install xauth

Whenever I try to run an application, like xterm & or xclock I get the same error:

PuTTY X11 proxy: Unsupported authorisation protocol
Error: Can't open display: localhost:10.0

I've combed the Internet and found a number of other people reporting the same problem, but no clear fix, at least that has worked for me. Anybody else solved this problem?

  • try adding localhost to your hosts file – user257256 May 14 '16 at 5:26

I was able to finally figure out a solution. The problem seems to have been with the .Xauthority file. The owner of the file was root (see below).

-rw-------  1 root   root      124 May 13 18:19 .Xauthority
-rw-------  2 ubuntu ubuntu      0 May 14 19:56 .Xauthority-c
-rw-------  2 ubuntu ubuntu      0 May 14 19:56 .Xauthority-l

I tried to delete the file and restart xauth and ssh but that didn't work so I removed xauth entirely using sudo apt-get purge xauth. Then I deleted all of the .Xauthority files in my home directory. Then I reinstalled xauth, again using sudo apt-get install xauth. The new .Xauthority file was owned by ubuntu.

-rw-------  1 ubuntu ubuntu    100 May 14 20:27 .Xauthority

I ended up testing Putty with the X display location of :localhost.0 as well as :0.0 but it didn't seem to matter since both worked. I then tested with xclock & and it popped right up, finally.

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