Raspberry Pi OS • "Can't connect to display" error on Raspberry Pi

Hi,

I have a project that has been developed over the last four years that I need to update due to the change in the Raspberry Pi hardware.
I created a new Micro-SD card that boots the current version of Linux and reinstalled all my libraries.
I (finally) have a clean build of my application, but I'm having a problem that I can't solve.
When I try to run my app, I get a "Can't connect to display" error.
I have tried everything I can find, but it still doesn't work.

I know that Xserver is running...
laser@raspberrypi:~ $ ps aux | grep xserver
laser 3950 0.0 0.0 7448 520 pts/1 S+ 00:42 0:00 grep --color=auto xserver

I have tried naming the display...
laser@raspberrypi:~ $ export DISPLAY=:0.0
laser@raspberrypi:~ $ echo $DISPLAY
:0.0

I have done updates...
sudo apt update
sudo apt upgrade

I updated the graphics drivers

Xserver logs don't exist, so no help there.

A simple test shows the error...
laser@raspberrypi:~ $ xset +
xset: unable to open display ":0.0"

At this point, I am completely flummoxed.

HELP!

Thanks...

- al

Statistics: Posted by laughingcat — Wed Mar 06, 2024 7:58 am

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