[GearVR] Crash on Input (except when Oculus GearVR Home is uninstalled)

Hello everybody!

I have an Unreal Engine 4.20.2 project that until recently worked fine until it started to crash on any input (especially noteworthy: ).
The crash happens on Samsung Galaxy S8 edge, Oculus GO reportidly works fine.

Most suspiciously, I can get the intended behaviour (buttons not causing the app to crash) by following these steps:

Install App and launch (crashes)
Start GearVR developer mode
Uninstall GearVR version of Oculus Home from the App Launcher (not the App list in settings)
Since the GearVR service is still running, I can still launch the App, which then works fine

Alternatively installing Oculus Home without logging in supposidly also works.
This makes me think it could be related to entitlement checks, but adb logcat output gives me no hints.
The crash happens in some Android Event Thread, here are some stack traces Android Studio gave me while debugging, no idea if they are useful to anyone:

Image: https://cdn.discordapp.com/attachments/441537477904433153/485191037971595264/unknown.png

Image: https://cdn.discordapp.com/attachments/441537477904433153/485189969871110155/unknown.png

Any idea or even guess would be super appreciated.

Looking forward to your comments!
Cheers, Jonathan.

Other things I tried (for reference):

Target/Minimum SDK is currently 24, but changing to 19 does not seem to affect this. I admit I am not experienced with the Android SDK or NDK, so I may still be building with 24, not totally sure
Using Unreal Engine 4.20.1 does not fix the issue
I cannot reproduce on Rift (just to make sure the input handling code on the project side is more or less sane)
The app doesn't crash immediately on button press, but with a short, variable length delay.
Starting the App without the developer mode trick does not work, it prompts you to install all the Oculus Apps
Rolling back to the last "known to work build" on the Oculus store causes the same problem
volume controls also lead to the crash which are definitely not handled by the project
I cannot reproduce it with the GearVR Motion Controller example from Unreal Engine (it works totally fine), but that is neither built for distribution nor installed via Oculus Home.

25 Replies

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redhill71
Explorer
8 years ago

imperativity said:

@Squareys

Can you private message me the name of your application and dev org so I can look into this?

Our game in the store is having the same problem as above. Is there a way to solve it?
Squareys
Explorer
8 years ago
@redhill71
I have not yet received an answer from @imperativity
Anonymous
8 years ago
@imperativity same problem here with our app (found out through 1 star complaining ratings coming in). It appears to be related to one of the latest Oculus GearVR app updates as this problem did not previously occur when our last 4.20 update was uploaded.

Is there any update on how to fix?

Any input by the user on either the GearVR headset or GearVR controller results in a crash. Go version works fine.
ACA3D
Honored Guest
8 years ago
I have the same problem. Unreal Engine 4.20.2 and Samsung Galaxy S8. Also tested and have it with Samsung Galaxy S7.
Any input by the user on either the GearVR headset or GearVR controller results in a crash. Go version works fine.
Anonymous
8 years ago

imperativity said:

I have opened an internal task to dig into this issue on our end. I will update this thread when I have more information or a fix to share.

@imperativity Thanks!

What I've found is if I change the bundleId, rename my project, or create any new project the crash does not occur. It's only when the project matches the bundle id of the app in the oculus store. Perhaps something changed on the entitlement side for official apps? But strange it only kicks in after some input...
DolloD
Protege
8 years ago
I can confirm this error too. Our app on the store is broken on Gear and getting bad reviews due to this problem. Confirm changing the bundleID makes it work and not seeing problem on the GO.
Our app runs UE4.18.3
Here is the output from Android Studio:

09-19 12:45:28.397 14659-14659/? A/DEBUG: signal 4 (SIGILL), code -6 (SI_TKILL), fault addr 0x3870
...
09-19 12:45:28.461 14659-14659/? A/DEBUG: backtrace:
09-19 12:45:28.463 14659-14659/? A/DEBUG: #00 pc 00000598 /system/lib/libandroid.so (offset 0xa000)
09-19 12:45:28.463 14659-14659/? A/DEBUG: #01 pc 01f4ce08 /data/app/[redacted]/lib/arm/libUE4.so
09-19 12:45:28.463 14659-14659/? A/DEBUG: #02 pc 01f2d414 /data/app/[redacted]/lib/arm/libUE4.so
09-19 12:45:28.463 14659-14659/? A/DEBUG: #03 pc 00047493 /system/lib/libc.so (_ZL15__pthread_startPv+22)
09-19 12:45:28.463 14659-14659/? A/DEBUG: #04 pc 00019f6d /system/lib/libc.so (__start_thread+6).

The thread this runs on seems to be the Android event loop. The crux of the matter is SIGILL which means from my limited understanding its running an illegal instruction such as addressing register 16 when only 0-15 are allowed. Since the error happens in libandroid.so from the NDK libraries its possible that some update on the GearVR with respect to the home app and the controller causes some messaging protocol from the controller that breaks under the ndk. I tried compiling with NDK 1.7 and that didn't work, nor did switching from android 21 to android 24. I beat my head against the wall for a couple of days trying to find this one. Thank God for dr. google, but it looks like its nigh impossible for us to work around this problem and so we eagerly await a fix. Thank you
Anonymous
8 years ago

imperativity said:

@Squareys
@redhill71
@aussieburgerVR
@ACA3D
@tomotor

Can you try the command "adb shell setprop debug.oculus.enablebreakpad 0" on your applications and let me know if this resolves the issue?

@imperativity running that command before starting the app did indeed resolve the issue.

I'm also PM'ing you my log files and a super simple example project to reproduce it. The logs are spammed constantly with:

LogOcInput: Get touchpad main with data 0.000000 0.000000

with the error line being:

Fatal signal 4 (SIGILL), code -6, fault addr 0x5f01 in tid 24392 (Thread-3)
Squareys
Explorer
8 years ago
@imperativity
adb shell setprop debug.oculus.enablebreakpad 0

Prevents the issue for me aswell!

The spamming that @aussieburgerVR mentioned happens for me, too, especially during debugging from the UE4 editor. I don't believe it it related to this issue, but maybe that could bubble up to the SDK/UE4 plugin devs, would make adb logcat output a lot more readible. ;-)
rpalandri
Expert Protege
8 years ago
Sorry for the log spam I didn't notice it. I removed it from the future builds. It'll be in our next github integration and in 4.21.
Anonymous
8 years ago

imperativity said:

A fix will be coming for this issue on 10/2/18 via an Oculus software update.

Thanks for the update. It's a bit disappointing to be honest to have to wait 11 days for the fix to a breaking change without any workaround for users (other than getting a Go). Hopefully there is no hugely popular game needing to wait that long...

Still better than no fix I guess ;)