[BUG] I see only a black screen when I open Session Desktop

[michael10101]

Code of conduct

• I have read and agree to adhere to the Code of Conduct

Self-training on how to write a bug report

• I have learned how to write a bug report

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

The screen goes black when I open Session desktop app.

I open session by this command:

flatpak run network.loki.Session

Some output(logs) of terminal:

// Fragment GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
out mediump vec4 sk_FragColor;
noperspective in mediump vec4 vcolor_S0;
void main() {
    mediump vec4 outputColor_S0;
    outputColor_S0 = vcolor_S0;
    {
        sk_FragColor = outputColor_S0;
    }
}


Errors:
link failed but did not provide an info log
[42:0105/134027.073398:ERROR:shared_context_state.cc(81)] Skia shader compilation error
------------------------
// Vertex SKSL
#extension GL_NV_shader_noperspective_interpolation: require
uniform float4 sk_RTAdjust;in float2 position;in half4 color;flat out half4 vcolor_S0;void main() {// Primitive Processor QuadPerEdgeAAGeometryProcessor
vcolor_S0 = color;sk_Position = position.xy01;}
// Fragment SKSL
#extension GL_NV_shader_noperspective_interpolation: require
flat in half4 vcolor_S0;void main() {// Stage 0, QuadPerEdgeAAGeometryProcessor
half4 outputColor_S0;outputColor_S0 = vcolor_S0;const half4 outputCoverage_S0 = half4(1);{ // Xfer Processor: Porter Duff
sk_FragColor = outputColor_S0 * outputCoverage_S0;}}
// Vertex GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
uniform highp vec4 sk_RTAdjust;
in highp vec2 position;
in mediump vec4 color;
flat out mediump vec4 vcolor_S0;
void main() {
    vcolor_S0 = color;
    gl_Position = vec4(position, 0.0, 1.0);
    gl_Position = vec4(gl_Position.xy * sk_RTAdjust.xz + gl_Position.ww * sk_RTAdjust.yw, 0.0, gl_Position.w);
}

// Fragment GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
out mediump vec4 sk_FragColor;
flat in mediump vec4 vcolor_S0;
void main() {
    mediump vec4 outputColor_S0;
    outputColor_S0 = vcolor_S0;
    {
        sk_FragColor = outputColor_S0;
    }
}


Errors:
link failed but did not provide an info log
[42:0105/134027.074030:ERROR:shared_context_state.cc(81)] Skia shader compilation error
------------------------
// Vertex SKSL
#extension GL_NV_shader_noperspective_interpolation: require
uniform float4 sk_RTAdjust;in float2 position;in half4 color;flat out half4 vcolor_S0;void main() {// Primitive Processor QuadPerEdgeAAGeometryProcessor
vcolor_S0 = color;sk_Position = position.xy01;}
// Fragment SKSL
#extension GL_NV_shader_noperspective_interpolation: require
flat in half4 vcolor_S0;void main() {// Stage 0, QuadPerEdgeAAGeometryProcessor
half4 outputColor_S0;outputColor_S0 = vcolor_S0;const half4 outputCoverage_S0 = half4(1);{ // Xfer Processor: Porter Duff
sk_FragColor = outputColor_S0 * outputCoverage_S0;}}
// Vertex GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
uniform highp vec4 sk_RTAdjust;
in highp vec2 position;
in mediump vec4 color;
flat out mediump vec4 vcolor_S0;
void main() {
    vcolor_S0 = color;
    gl_Position = vec4(position, 0.0, 1.0);
    gl_Position = vec4(gl_Position.xy * sk_RTAdjust.xz + gl_Position.ww * sk_RTAdjust.yw, 0.0, gl_Position.w);
}

// Fragment GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
out mediump vec4 sk_FragColor;
flat in mediump vec4 vcolor_S0;
void main() {
    mediump vec4 outputColor_S0;
    outputColor_S0 = vcolor_S0;
    {
        sk_FragColor = outputColor_S0;
    }
}


Errors:
link failed but did not provide an info log
[42:0105/134027.074836:ERROR:shared_context_state.cc(81)] Skia shader compilation error
------------------------
// Vertex SKSL
#extension GL_NV_shader_noperspective_interpolation: require
uniform float4 sk_RTAdjust;in float2 inPosition;in half4 inColor;in float4 inCircleEdge;noperspective out float4 vinCircleEdge_S0;noperspective out half4 vinColor_S0;void main() {// Primitive Processor CircleGeometryProcessor
vinCircleEdge_S0 = inCircleEdge;vinColor_S0 = inColor;float2 _tmp_0_inPosition = inPosition;float2 _tmp_2_inPosition = inPosition;sk_Position = _tmp_0_inPosition.xy01;}
// Fragment SKSL
#extension GL_NV_shader_noperspective_interpolation: require
noperspective in float4 vinCircleEdge_S0;noperspective in half4 vinColor_S0;void main() {// Stage 0, CircleGeometryProcessor
float4 circleEdge;circleEdge = vinCircleEdge_S0;half4 outputColor_S0;outputColor_S0 = vinColor_S0;float d = length(circleEdge.xy);half distanceToOuterEdge = half(circleEdge.z * (1.0 - d));half edgeAlpha = saturate(distanceToOuterEdge);half distanceToInnerEdge = half(circleEdge.z * (d - circleEdge.w));half innerAlpha = saturate(distanceToInnerEdge);edgeAlpha *= innerAlpha;half4 outputCoverage_S0 = half4(edgeAlpha);{ // Xfer Processor: Porter Duff
sk_FragColor = outputColor_S0 * outputCoverage_S0;}}
// Vertex GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
uniform highp vec4 sk_RTAdjust;
in highp vec2 inPosition;
in mediump vec4 inColor;
in highp vec4 inCircleEdge;
noperspective out highp vec4 vinCircleEdge_S0;
noperspective out mediump vec4 vinColor_S0;
void main() {
    vinCircleEdge_S0 = inCircleEdge;
    vinColor_S0 = inColor;
    highp vec2 _tmp_0_inPosition = inPosition;
    gl_Position = vec4(_tmp_0_inPosition, 0.0, 1.0);
    gl_Position = vec4(gl_Position.xy * sk_RTAdjust.xz + gl_Position.ww * sk_RTAdjust.yw, 0.0, gl_Position.w);
}

// Fragment GLSL
#version 300 es

#extension GL_NV_shader_noperspective_interpolation : require
precision mediump float;
precision mediump sampler2D;
out mediump vec4 sk_FragColor;
noperspective in highp vec4 vinCircleEdge_S0;
noperspective in mediump vec4 vinColor_S0;
void main() {
    highp vec4 circleEdge;
    circleEdge = vinCircleEdge_S0;
    mediump vec4 outputColor_S0;
    outputColor_S0 = vinColor_S0;
    highp float d = length(circleEdge.xy);
    mediump float distanceToOuterEdge = circleEdge.z * (1.0 - d);
    mediump float edgeAlpha = clamp(distanceToOuterEdge, 0.0, 1.0);
    mediump float distanceToInnerEdge = circleEdge.z * (d - circleEdge.w);
    mediump float innerAlpha = clamp(distanceToInnerEdge, 0.0, 1.0);
    edgeAlpha *= innerAlpha;
    mediump vec4 outputCoverage_S0 = vec4(edgeAlpha);
    {
        sk_FragColor = outputColor_S0 * outputCoverage_S0;
    }
}


Errors:
link failed but did not provide an info log
[42:0105/134027.075504:ERROR:shared_context_state.cc(81)] Skia shader compilation error

NOTE-1

If I close the session desktop app, and then I remove "$HOME/.var/app/network.loki.Session" and I start again the desktop app, session works properly. But after few days the UI goes blank.

NOTE-2

If the black screen bug exist, I can still see the "file-edit-view-window-help" menu if I click "ALT" button from my keyboard.

I think the UI objects are rendered, but they are fully black. Because If I move my mouse pointer somewhere on black screen, the pointer icon changes sometimes. I think I can click the buttons etc, but I can not see anything. Because they are black.

NOTE-3

I try to use dark mode of Gnome but nothing changed.

NOTE-4

Signal desktop app works properly which is also installed on my OS via flatpak.

Expected Behavior

No response

Steps To Reproduce

1. Install flatpak session desktop app.
2. use Session desktop app a few days.
3. the UI is black when I open session desktop app again.

Desktop Version

1.14.3

Anything else?

• Fedora Linux 41 (Workstation Edition) (64 bit) (stable version) (The OS is clean/fresh installed)
• My session is installed via Flatpak.

[KeeJef]

tracked internally via SES-3169

[Bilb]

Hey @michael10101 ,
could you try and let me know if this fixes your issue (reliably)? ferdium/ferdium-app#1265 (comment)

[Bilb]

I gave the flatpak a try but I don't see to reproduce this on ubuntu

[michael10101]

@Bilb I remove this directory completly manually:

$HOME/.var/app/network.loki.Session/config/Session/GPUCache

now I dont have any problem. everything is OK. Thank you

[ngrigoriev]

I have just experienced this on latest Arch Linux with Session app 1.14.5. It has happened after AMD GPU reset, which happens from time to time on my hardware. I have restarted the machine and Session Desktop has shown the black window after the launch. It was clearly working because the cursor changed shapes when hovering over the places where various controls were supposed to be. Other apps, like Signal etc, worked correctly.

Removing GPUCache directory from ~/.config/Session did solve the problem.

[michael10101]

By the way I have nvidia-GPU on my laptop. But it is fully disabled. I use only the CPU's-embeeded-GPU.

[ngrigoriev]

@michael10101 Nvidia GPUs in Linux specifically on the laptops are the endless sources of complains. But here the problem is unlikely the hardware, so the GPU family does not matter. I do not know what Skia shader is, but, my guess, is that something persisted (!) in the disk cache is either corrupted or becomes incompatible with the new version of the library used by the app. IMO, given the relative simplicity of the application's GUI, emptying this cache on startup may not be such as bad thing to do.