$ kwrite Invalid MIT-MAGIC-COOKIE-1 key qt.qpa.xcb: could not connect to display :0 qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found. This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
$ kwrite Invalid MIT-MAGIC-COOKIE-1 key qt.qpa.xcb: could not connect to display :0 qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found. This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
i'll start with the most obvious. The error says to reinstall xcb. Did you try that while connected to wifi?
Title: Re: no applications start after WiFi connects
Post by: gripped on 12 June 2022, 20:30:55
I seem to remember hearing about issues along the lines of problems with X because NetworkManager was changing the hostname when establishing a connection and X expects the hostname to stay the same once started.
But this is only a vague memory. I've had a search on here but can't find the post so maybe it was a dream :)
$ kwrite Invalid MIT-MAGIC-COOKIE-1 key qt.qpa.xcb: could not connect to display :0 qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found. This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
I have had that problem on the live iso of that flavour in the past. I did find that on installation the problem disappears.
@gripped is correct that it is the hostname that causes the problem, though I can't remember the solution. However, I found that by opening the installer and/or any other programs you need to run BEFORE connecting to wifi, I was able to install satisfactorily.
Title: Re: no applications start after WiFi connects
Post by: francesco on 14 June 2022, 08:37:34
Hi. I got the same problem with 3 notebooks and I solved it modifying /etc/NetworkManager/NetworkManager.conf in this way:
[main] plugins=keyfile hostname-node=none
I'm using networkmanager, but in the last installation I got the same problem with connman. Probably I'll replace connman with networkmanager, if I wont be able to find a solution with connman.
Title: Re: no applications start after WiFi connects
Post by: ndowens on 17 June 2022, 02:20:13
Just updated networkmanager with the changes in the conf file. After next update is available on your mirror, it should work as expected.
Title: Re: no applications start after WiFi connects
Post by: n00b on 19 June 2022, 21:01:45
I seem to remember hearing about issues along the lines of problems with X because NetworkManager was changing the hostname when establishing a connection and X expects the hostname to stay the same once started.
But this is only a vague memory. I've had a search on here but can't find the post so maybe it was a dream :)