Hi, after some update cannot open VLC. i get this :
Widget::setMinimumSize: (/FirstRun) Negative sizes (-492131588,-492131668) are not possible
QXcbConnection: XCB error: 2 (BadValue), sequence: 419, resource id: 0, major code: 1 (CreateWindow), minor code: 0
QXcbConnection: XCB error: 3 (BadWindow), sequence: 420, resource id: 18874373, major code: 2 (ChangeWindowAttributes), minor code: 0
QXcbConnection: XCB error: 3 (BadWindow), sequence: 421, resource id: 18874373, major code: 18 (ChangeProperty), minor code: 0
QXcbConnection: XCB error: 3 (BadWindow), sequence: 422, resource id: 18874373, major code: 18 (ChangeProperty), minor code: 0

Do you know how to fix it?

what was that "some update" exactly?

I dont know maybe VLC. I can open VLC only under vnc connection. I tried update nvidia driver but still doesnt work.

Hi,
I am having the same issue with VLC since some recent updates in Debian.
What I discovered so far:
The bug is only triggered, when there is a second monitor connected to my system.
Can you verify this?
1. Disconnect a second monitor
2. Start VLC
3. Enable the second monitor again should work.
Some others seem to have the same issue:
https://github.com/Studio3T/robomongo/issues/1289
Its the same error message, so I guess the bug is somewhere in QT.

Only back to version 2 help me to solve this problem

sudo apt remove vlc
sudo apt clean
sudo apt autoremove
sudo dpkg --list | grep ^rc
sudo dpkg --purge `dpkg --get-selections | awk '/deinstall/ {print $1}'`
cd ~/.config
rm -rf vlc

sudo apt-get install vlc=2.2.7-1~deb9u1 vlc-bin=2.2.7-1~deb9u1 vlc-plugin-base=2.2.7-1~deb9u1 vlc-plugin-qt=2.2.7-1~deb9u1 vlc-plugin-video-output=2.2.7-1~deb9u1 vlc-l10n=2.2.7-1~deb9u1 vlc-plugin-notify=2.2.7-1~deb9u1 vlc-plugin-samba=2.2.7-1~deb9u1 vlc-plugin-skins2=2.2.7-1~deb9u1 vlc-plugin-video-splitter=2.2.7-1~deb9u1 vlc-plugin-visualization=2.2.7-1~deb9u1 libvlc-bin=2.2.7-1~deb9u1 vlc-data=2.2.7-1~deb9u1 libvlc5=2.2.7-1~deb9u1

I don't think removing and reinstalling is going to work. It seems to be a problem with one of the qt5 packages needing to be updated. I would report it as a bug.

^ yes, there's been various reports about Qt related problems with VLC.

thankfully, on Linux there's excellent native alternatives so no harm. you can still watch your movies.

I have tried everything trying to get VLC 3 to work properly:
Under Debian, 3.0.3 wont start with QT and a second monitor enabled at the startup. The ncurses version works, however.
Once DVD playback starts, the video starts to stall at some random position (slideshow) and can only get to play proper again, when selecting a slightly different position after the problematic position with the mouse. Not very comfortable when you wand to just watch a DVD...
On the video output filters:
XVideo -> works with the problems described above.
X11 Video -> works with the problems described above.
Open GL -> works, but the menu has some serious overlay errors, so you cant be sure which menu item is currently selected.
Video memory output -> not working
Flaschen-Taschen -> not working
Ascii -> not working
Wayland -> not working
GNU/Linux framebuffer -> not working
YUV -> not working
My graphic card is a Radeon using open source drivers and games like Civilization 6 work well with it.

The 2.2.8 version wont compile under Debian as the libavutil versions 55 (found in Debian) is not supported (too new).
The 3.0.3 Windows 64bit version with WINE wont show any video regardless of the selected video output.
The 2.2.8 windows 64bit version with WINE shows a video when selecting Windows GDI as output. For me, this version seems to work best. Could laugh about it if it would not be soo sad...