[OnePlus 6 ROMs, Kernels, Recoveries, & Other Devel] bdick21:
Hi Flying Fox, I tried your suggestion and kept deleting EX Kernel Manager's data until the buttons greyed out (in app info), but it still crashed. It was a good suggestion and definitely worth a try. Keep the suggestions coming! Eventually we'll crack it. Many thanks!

---------- Post added at 11:16 PM ---------- Previous post was at 11:10 PM ----------

Thank you magnamentis for contacting flar2 for me! That was very kind of you.

I tried your suggestion of locking the bootloader, then I upgraded to Oxygen 5.1.7 via Settings, unlocked the bootloader, fastbooted twrp, then installed twrp installer, reboot recovery, install ElementalX 1.05 + Magisk 16.4, reboot system, but it still crashes!

Note that I installed 5.1.7 via Settings, not TWRP. Which might be a difference between what I do and what everybody else does.

Next I captured a logcat and the crash seems to be caused by an array out of bounds exception in com.android.settings.DisplaySettings.updateThemeModePreferenceDescription.

I'm using the Avengers theme. Could that be the difference between my phone and everybody else's that is causing the crash?

Next I'll clean install yet again and try switching to a different theme before flashing ElementalX. Fingers crossed that will solve it!

--------- beginning of crash

E/AndroidRuntime( 1968): FATAL EXCEPTION: main

E/AndroidRuntime( 1968): Process: com.android.settings, PID: 1968

E/AndroidRuntime( 1968): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.settings/com.android.settings.Settings$DisplaySettingsActivity}: java.lang.ArrayIndexOutOfBoundsException: length=3; index=3

E/AndroidRuntime( 1968):	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2911)

E/AndroidRuntime( 1968):	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2989)

E/AndroidRuntime( 1968):	at android.app.ActivityThread.-wrap11(Unknown Source:0)

E/AndroidRuntime( 1968):	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1688)

E/AndroidRuntime( 1968):	at android.os.Handler.dispatchMessage(Handler.java:106)

E/AndroidRuntime( 1968):	at android.os.Looper.loop(Looper.java:164)

E/AndroidRuntime( 1968):	at android.app.ActivityThread.main(ActivityThread.java:6753)

E/AndroidRuntime( 1968):	at java.lang.reflect.Method.invoke(Native Method)

E/AndroidRuntime( 1968):	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:482)

E/AndroidRuntime( 1968):	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

E/AndroidRuntime( 1968): Caused by: java.lang.ArrayIndexOutOfBoundsException: length=3; index=3

E/AndroidRuntime( 1968):	at com.android.settings.DisplaySettings.updateThemeModePreferenceDescription(DisplaySettings.java:1370)

E/AndroidRuntime( 1968):	at com.android.settings.DisplaySettings.onCreate(DisplaySettings.java:505)

E/AndroidRuntime( 1968):	at android.app.Fragment.performCreate(Fragment.java:2489)

E/AndroidRuntime( 1968):	at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1237)

E/AndroidRuntime( 1968):	at android.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1319)

E/AndroidRuntime( 1968):	at android.app.FragmentTransition.calculateFragments(FragmentTransition.java:1203)

E/AndroidRuntime( 1968):	at android.app.FragmentTransition.startTransitions(FragmentTransition.java:101)

E/AndroidRuntime( 1968):	at android.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2178)

E/AndroidRuntime( 1968):	at android.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2136)

E/AndroidRuntime( 1968):	at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2043)

E/AndroidRuntime( 1968):	at android.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:799)

E/AndroidRuntime( 1968):	at com.android.settings.SettingsActivity.switchToFragment(SettingsActivity.java:1428)

E/AndroidRuntime( 1968):	at com.android.settings.SettingsActivity.onCreate(SettingsActivity.java:928)

E/AndroidRuntime( 1968):	at com.android.settings.RencentSettings.onCreate(RencentSettings.java:25)

E/AndroidRuntime( 1968):	at android.app.Activity.performCreate(Activity.java:7036)

E/AndroidRuntime( 1968):	at android.app.Activity.performCreate(Activity.java:7027)

E/AndroidRuntime( 1968):	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1231)

E/AndroidRuntime( 1968):	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2864)

E/AndroidRuntime( 1968):	... 9 more