x11vnc XOpenDisplay failed (:0)
 

running fedora 25 and I keep getting this error when running x11vnc. I also tried xllvnx -create but that gives a black screen that times out and disappears after a few seconds. I've been trawling google but can't find a solution for fedora 25, thanks for any help.

would be nice to explain how did you try it. Probably it is a permission related issue.

Probably a wayland issue.

@pan94 I logged in to the machine as root using putty from another machine on the LAN and typed x11vnc but it always gives this error. I also tried logging in as the user but that gives the same error. If it's a permission issue what do I need to give permission to?

In this case the problem is (as I see) the X started by a user and noone else has access to this X session (even root has no access rights).
So first you need to set DISPLAY before starting x11vnc (but probably that was already set) and also need to execute xhost + on that host (not from a putty terminal, but from GUI). xhost + is not the best solution, but you can check if it helps at all.

thanks for your response, still no joy.
I did xhost in a terminal on the physical machine and it gave:
I also did
but still I get XOpenDisplay failed (:0) when running x11vnc. I've also tried x11vnc -display :1, and :2 but they failed. x11vnc -display disp also fails, along with x11vnc -find
x11vnc -create does work but it gives me a black screen. Any further ideas appreciated.

did you check: x11vnc -display :0 ?

thanks yeah I tried that, it gave a different error:

probably this helps: https://forum.winehq.org/viewtopic.php?t=7048
something (some packages/libraries are missing or incompatible with each others, or 64/32bit mismatch...)

thanks but I'm still scratching my head after reading the link you gave. I tried a different graphics card in the machine but it made no difference. If there is a package mismatch I don't know what that package would be or how to fix it.

since you gave no information about your system it will be really hard (even guess) from here.
Probably you can find something usable here: https://askubuntu.com/questions/2299...-login-screen/

this is a brand new install of fedora 25, x11vnc is the first thing installed on it

solved: xfce desktop did the trick, I'm now in with x11vnc. Thankyou for your help pan64

glad to help you.
if you really want to say thanks just click on yes