[Magisk] Dc0de:
This problem definitely seems to be linked with searching for updates or something. If I put my phone into airplane mode, I can get into Magisk Manager with no crash...I then can turn off airplane mode...but the download modules tab is empty...just a busy sign. Internet works fine and can run a safety net check ok (it doesn't pass but does run and return a result).

The crash on Magisk Manager startup produces these logs if airplane mode is off (sorry still can't attach logs in txt file):

08-05 16:19:11.975 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:13.210 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:13.428 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:13.979 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:14.372 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:14.838 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:15.266 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:15.695 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:16.243 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:16.320 E/MMSDK-Handshake <660:1501946356320>(14744): Handshake request failed with HTTP response code: 408

08-05 16:19:16.428 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:17.163 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:17.446 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:17.653 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:17.909 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:18.339 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:18.758 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:19.186 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:19.428 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:20.104 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:20.349 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:20.667 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:21.579 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:22.125 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:22.428 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:22.691 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:23.065 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:24.345 E/AndroidRuntime(24441): FATAL EXCEPTION: AsyncTask #3

08-05 16:19:24.345 E/AndroidRuntime(24441): Process: com.topjohnwu.magisk, PID: 24441

08-05 16:19:24.345 E/AndroidRuntime(24441): Theme: themes:{}

08-05 16:19:24.345 E/AndroidRuntime(24441): java.lang.RuntimeException: An error occurred while executing doInBackground()

08-05 16:19:24.345 E/AndroidRuntime(24441): at android.os.AsyncTask$3.done(AsyncTask.java:309)

08-05 16:19:24.345 E/AndroidRuntime(24441): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)

08-05 16:19:24.345 E/AndroidRuntime(24441): at java.util.concurrent.FutureTask.setException(FutureTask.java:223)

08-05 16:19:24.345 E/AndroidRuntime(24441): at java.util.concurrent.FutureTask.run(FutureTask.java:242)

08-05 16:19:24.345 E/AndroidRuntime(24441): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)

08-05 16:19:24.345 E/AndroidRuntime(24441): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)

08-05 16:19:24.345 E/AndroidRuntime(24441): at java.lang.Thread.run(Thread.java:818)

08-05 16:19:24.345 E/AndroidRuntime(24441): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.WeakReference.get()' on a null object reference

08-05 16:19:24.345 E/AndroidRuntime(24441): at com.topjohnwu.magisk.a.f.g(Unknown Source)

08-05 16:19:24.345 E/AndroidRuntime(24441): at com.topjohnwu.magisk.a.f.h(Unknown Source)

08-05 16:19:24.345 E/AndroidRuntime(24441): at com.topjohnwu.magisk.a.b.a(Unknown Source)

08-05 16:19:24.345 E/AndroidRuntime(24441): at com.topjohnwu.magisk.a.b.doInBackground(Unknown Source)

08-05 16:19:24.345 E/AndroidRuntime(24441): at android.os.AsyncTask$2.call(AsyncTask.java:295)

08-05 16:19:24.345 E/AndroidRuntime(24441): at java.util.concurrent.FutureTask.run(FutureTask.java:237)

08-05 16:19:24.345 E/AndroidRuntime(24441): ... 3 more

08-05 16:19:25.420 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:28.422 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:31.428 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:32.582 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:34.421 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:35.236 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]

08-05 16:19:37.420 E/NONXPOSED_NOTIFYING_SERVICE(8367): XPOSED RUNNING, BUG REPORTS ARE USELESS!!!!

08-05 16:19:38.045 E/ANDR-PERF-RESOURCEQS(6974): Failed to apply optimization [4, 1]