CTD when texture goes null mid update

[thormj]

I've been trying to get interaction working (no idea.... the rest of my project uses BRB's; right now no UGUIs are interactable).
But... if something happens to the texture mid update... the whole getup will crash to desktop.

I have a permissions handler thing... that flickers back and forth as it tries [but fails] to use the system to ask for permissions...
I have a grabbable cube attached to the side of the browser as a "handle" and it moves the Browser GO.
If you grab it... and move it and a SysRq or a permissions thing causes appfocuschange... boom.

Claude said this about the attached bugreport:

Crystal clear crash. The culprit chain:
SIGSEGV — null pointer dereference in tlab::RenderAPI_Vulkan::UpdateUnityTexture
#3 libshared-texture.so tlab::RenderAPI_Vulkan::UpdateUnityTexture(long, long)+220
#4-#8 com.tlab.webkit.BaseOffscreenFragment.UpdateSharedTexture
TLabWebView is trying to update its shared Vulkan texture during a frame render, and the underlying Vulkan texture handle has gone null. This happens when something interrupts the render pipeline mid-frame — grabbing the bar and moving it triggers a transform update which apparently invalidates the texture handle momentarily, and TLab's native code dereferences a null pointer.
This is a TLabWebView bug — UpdateUnityTexture should null-check before dereferencing. You could file it on their GitHub, but the workaround is: don't grab/move the WebView quad while it's actively rendering. Or switch to a parent GO grab where the WebView canvas is a child — the parent moves, the WebView texture never gets directly touched by the grab physics.

But my Cube is actually on an Ego that is the parent of the BrowserSample object, so... yeah. This crash happened when I had just finished "punching" the dialog [no response], and hit SysReq button to go select "application quit"... but she died instead.

bugreport-eureka-UP1A.231005.007.A1-2026-06-24-08-59-21.zip

[thormj]

Another crash with maybe some clues. Was fine sitting on the youtube page for a minute or so... so I clicked on Michael Jackson's Smooth Criminal video.
Add played fine... transitioned into the video...about 45 seconds in (where the coin hits the jukebox) and the beat drops and things go into high motion... Crash to desktop.

bugreport-eureka-UP1A.231005.007.A1-2026-06-28-20-07-47.zip

Does the WebView not like video? Now trying with slashdot.org to see if text is all good because that's mainly what I need... text and javascript links to program variables...

[thormj]

Tried with a wall of text... displayed fine, but when I was dragging it down [scroll by drag?], another crash to desktop.
Note that the TLabWebViewVR example... works... all the way through Michael Jackson.

But I don't know what I'm doing different -- I exported TLabWebViewVR's prefab and imported it into my project and... though I can see... it dies. I tried the other rendering options, but they just give me a white box with sound coming out of it.

bugreport-eureka-UP1A.231005.007.A1-2026-06-28-21-41-41.zip

Target Device: Q3, MR PassThru, MRUK 85.0.0 Unity 6000.3.9f1

[TLabAltoh]

Hi @thormj. Thank you for the report. I’ve been a bit busy lately, and I’m sorry I haven’t been able to devote much time to maintaining this repository. My response might be a little delayed, so I hope you’ll bear with me.

To be honest, I haven’t had a chance to read the bug reports you attached yet, so I’m commenting based on my current understanding, but I’d like to share my thoughts.

First, I think your observation that WebView struggles with video processing is spot on. To reduce the load on the device—especially on the Quest—it might be necessary to take measures such as lowering the WebView resolution when displaying videos. Currently, we haven’t implemented recovery mechanisms for when the process crashes due to high load (setting aside the question of whether crashes caused by high load should even be recoverable in the first place), so I’d like you to adjust the app to prevent the load from becoming too high, taking into account which devices are being targeted.

I’d like to dig a little deeper into isolating the cause of crashes and other issues that occur when dragging the text display screen. For now, I plan to review the bug report you attached when I have some time. I’m sure I’ll have some questions to help narrow down the problem, so I’d really appreciate your cooperation when that time comes.

[thormj]

No problem. I was just trying... got it to work, but it crashed, so I figured I'd try another way and another way and...
I wasn't intending to sound impatient or worse, just figured it would be useful (?) if you could see the rabbit holes I've already been down.

Like I said the really odd part is... the demo scene from TLabWebViewVR works and works with youtube. But I have no idea what I'm doing "different" in my scene... except that your demo is on the Unity it shipped with -- 2022.3.19f1.git.2378610
Revision: 2022.3/staging 244b723c30a6
Built: Thu, 25 Jan 2024 15:28:30 GMT ... not sure which meta...

And mine is on 6000.3.9f1 ... MetaAllInOne 85.0.0

[thormj]

Found it!
If you Enable Legacy Graphics Jobs (project settings->Player)... it won't make it thru Smooth Criminal (so do not enable that meta-recommended fix!). You uncheck the box, and we do mostly fine.

I think it works a little more smoothly if you add ETC to the Texture Compression (beyond the Meta-recommended ASTC).

So maybe add notes about those 2 settings to the Set Up section. Whew. Now back to fighting with trying to get it to load html files out of the filesystem...

[thormj]

So... PlainText is not allowed... different topic (should it be it's own issue request)...? Is there a good way to load HTML from the filesystem? Sheesh meta/android...