vnc viewer keeps black until moving or dragging the viewer window

[chiefliu]

Describe the bug

TigerVnc version :

I tried two versions fo TigerVnc. When i use tigervnc on windows10 LTSC to connect an Linux based on ubuntu and try to start an app
when the desktop is started . An turbovnc server （v3.0.3） is running on the linux，when connected the command line is on the linux :

/opt/TurboVNC/bin/Xvnc :1 -desktop TurboVNC: appbox:1 (root) -auth /root/.Xauthority -geometry 1240x900 -depth 24 -rfbwait 120000 -x509cert /root/.vnc/x509_cert.pem -x509key /root/.vn/x509_private.pem -securitytypes none -rfbport 30009 -fp catalogue:/etc/X11/fontpath.d -deferupdate 1 -dridir /usr/lib64/dri -registrydir /usr/lib64/xorg -nocursor -noclipboardrecv -noclipboardsend

It seems that the connection is successfully built,but the tigervnc windows keeps black:

if i move the tigervnc windows(such as drag the window，min size the max size)，it displays normally:

I'm not sure if this is an tigervnc bug or just some compatibility problems. Can you provide some solutions for troubleshooting this issue?

Client:
tigernvc 1.14.80
windows10 LTSC
windows dpi 1920*1080

server:
TurboVnc 3.0.3

Thank you ~

[chiefliu]

I use RealVNC 7.10, it works well

[CendioOssman]

To clarify, is it sufficient to just move the client window? Or do you need to resize it?

[chiefliu]

To clarify, is it sufficient to just move the client window? Or do you need to resize it?

I just make a test, i just moved the window, but the window size is changed. and if i minimize the window and then restore it. It comes to work normally too.

so I think i does not rely on resize?

[chiefliu]

I also found that the vnc viewer has a lot of white areas around the black area before i move it :

After i move the window, the white areas are disappeared:

[CendioOssman]

Did you use our builds for TigerVNC 1.14.80 and 1.3.1? Or did you build them yourself?

[chiefliu]

I use your builds, i didn't build it .

[chiefliu]

It works well in most cases except on windows10 LTSC

[CendioOssman]

I'm afraid that makes it almost impossible for us to debug and fix. :/

Does it work from that client to a TigerVNC server?

[chiefliu]

I did not do that test, I consider if this is a compatibility problem : when the vnc viewer is launched, the window size is not adjust correctly and may stuck the vnc viewer's display ? (As my previous screenshots, the vnc viewer window seems abnormal: there is a lot of white blank area)

[CendioOssman]

At this point it is difficult to state if that area comes from the client or the server. Hence why it would be very helpful if you can test with a different server.

[noarche]

Mine stays black the whole session. Not sure if it is because I do not have a monitor plugged in or what... Fixed by switching to LAN version of teamviewer free.

[CendioOssman]

@noarche, if you are not using Windows 10 LTSC then I don't think you have the same issue.

@chiefliu, please set up a test with TigerVNC as the server. That's the best way forward I can see.