title: Difficult to repeat signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x8
body: <p>I am struggling with a problem in Unity3D Android game. It is very hard to repeat Crash. It happens sometimes after 1 hour, sometimes 2 hours of playing every time in different situations and I can't find any reason.</p>
  <p>I have tried different versions of Unity:</p>
  <ul>
  <li>2020.2.1f1</li>
  <li>2019.3.12f1</li>
  </ul>
  <p>Also Mono and il2cpp compiler.</p>
  <p>Can anyone give me at least a hint how to find the cause?</p>
  <pre><code>01-28 12:40:56.797  5263  5291 E CRASH   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
  01-28 12:40:56.797  5263  5291 E CRASH   : Version '2020.2.1f1 (270dd8c3da1c)', Build type 'Release', Scripting Backend 'il2cpp', CPU 'armeabi-v7a'
  01-28 12:40:56.797  5263  5291 E CRASH   : Build fingerprint: 'Allwinner/t1_e1111/e1111:6.0.1/MMB29M/20200109:eng/test-keys'
  01-28 12:40:56.797  5263  5291 E CRASH   : Revision: '0'
  01-28 12:40:56.798  5263  5291 E CRASH   : ABI: 'arm'
  01-28 12:40:56.798  5263  5291 E CRASH   : Timestamp: 2021-01-28 12:40:56+0100
  01-28 12:40:56.798  5263  5291 E CRASH   : pid: 5263, tid: 5291, name: UnityMain  &gt;&gt;&gt; com.game.test &lt;&lt;&lt;
  01-28 12:40:56.799  5263  5291 E CRASH   : uid: 10038
  01-28 12:40:56.799  5263  5291 E CRASH   : signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x8
  01-28 12:40:56.799  5263  5291 E CRASH   : Cause: null pointer dereference
  01-28 12:40:56.799  5263  5291 E CRASH   :     r0  9e7054e0  r1  9e705c60  r2  9e705c60  r3  00000000
  01-28 12:40:56.799  5263  5291 E CRASH   :     r4  9e705c68  r5  00000001  r6  9e705c78  r7  9e705c60
  01-28 12:40:56.800  5263  5291 E CRASH   :     r8  a00392c0  r9  0002eeb0  r10 9e705c70  r11 00000000
  01-28 12:40:56.800  5263  5291 E CRASH   :     ip  00000001  sp  a09331c0  lr  00000000  pc  a29f21b8
  01-28 12:40:56.800  5263  5291 E CRASH   :
  01-28 12:40:56.800  5263  5291 E CRASH   : backtrace:
  01-28 12:40:56.800  5263  5291 E CRASH   :       #00 pc 000cd1b8  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.801  5263  5291 E CRASH   :       #01 pc 001047fd  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.801  5263  5291 E CRASH   :       #02 pc 00103083  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.801  5263  5291 E CRASH   :       #03 pc 00156493  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.801  5263  5291 E CRASH   :       #04 pc 001564af  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.802  5263  5291 E CRASH   :       #05 pc 00156649  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.802  5263  5291 E CRASH   :       #06 pc 0021612b  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.802  5263  5291 E CRASH   :       #07 pc 0022508d  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:56.803  5263  5291 E CRASH   :       #08 pc 000896b9  /data/app/com.game.test-1/oat/arm/base.odex
  01-28 12:40:57.169  5263  5291 E CRASH   : Tombstone written to: /storage/emulated/0/Android/data/com.game.test/files/tombstone_00
  --------- beginning of crash
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: FATAL EXCEPTION: UnityMain
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Process: com.game.test, PID: 5263
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: java.lang.Error: FATAL EXCEPTION [UnityMain]
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Unity version     : 2020.2.1f1
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Device model      : Allwinner_t1
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Device fingerprint: Allwinner/t1_e1111/t1111:6.0.1/MMB29M/20200109:eng/test-keys
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Build Type        : Release
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Scripting Backend : IL2CPP
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: ABI               : armeabi-v7a
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Strip Engine Code : true
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Caused by: java.lang.Error: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Version '2020.2.1f1 (270dd8c3da1c)', Build type 'Release', Scripting Backend 'il2cpp', CPU 'armeabi-v7a'
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Build fingerprint: 'Allwinner/t1_e1111/e1111:6.0.1/MMB29M/20200109:eng/test-keys'
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Revision: '0'
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: ABI: 'arm'
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Timestamp: 2021-01-28 12:40:56+0100
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: pid: 5263, tid: 5291, name: UnityMain  &gt;&gt;&gt; com.game.test &lt;&lt;&lt;
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: uid: 10038
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x8
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: Cause: null pointer dereference
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:     r0  9e7054e0  r1  9e705c60  r2  9e705c60  r3  00000000
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:     r4  9e705c68  r5  00000001  r6  9e705c78  r7  9e705c60
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:     r8  a00392c0  r9  0002eeb0  r10 9e705c70  r11 00000000
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:     ip  00000001  sp  a09331c0  lr  00000000  pc  a29f21b8
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:
  01-28 12:40:57.171  5263  5291 E AndroidRuntime: backtrace:
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #00 pc 000cd1b8  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #01 pc 001047fd  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #02 pc 00103083  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #03 pc 00156493  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #04 pc 001564af  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #05 pc 00156649  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #06 pc 0021612b  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #07 pc 0022508d  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:       #08 pc 000896b9  /data/app/com.game.test-1/oat/arm/base.odex
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0xcd1b8(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x1047fd(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x103083(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x156493(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x1564af(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x156649(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x21612b(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x22508d(Native Method)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at base.0x896b9(Native Method)
  01-28 12:40:57.175  2447  9872 W ActivityManager:   Force finishing activity com.game.test/com.unity3d.player.UnityPlayerActivity
  01-28 12:40:57.181  1659  4083 I [Gralloc]: ion_alloc from ion_client:17 via heap type DMA/CARVEOUT(mask:0x00000014) for 529920 Bytes cached buffer successfully, usage = 0x00000333
  01-28 12:40:57.235  2447 30702 D OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: false
  01-28 12:40:57.262  2447 30702 I OpenGLRenderer: Initialized EGL, version 1.4
  01-28 12:40:57.268  1659  1672 I [Gralloc]: ion_alloc from ion_client:17 via heap type DMA/CARVEOUT(mask:0x00000014) for 512000 Bytes uncached buffer successfully, usage = 0x00000f02
  01-28 12:40:57.270  1659  4083 I [Gralloc]: ion_alloc from ion_client:17 via heap type DMA/CARVEOUT(mask:0x00000014) for 512000 Bytes uncached buffer successfully, usage = 0x00000f02
  01-28 12:40:57.271  1659  4083 I [Gralloc]: ion_alloc from ion_client:17 via heap type DMA/CARVEOUT(mask:0x00000014) for 512000 Bytes uncached buffer successfully, usage = 0x00000f02
  01-28 12:40:57.271  1659  4083 I [Gralloc]: ion_alloc from ion_client:17 via heap type DMA/CARVEOUT(mask:0x00000014) for 512000 Bytes uncached buffer successfully, usage = 0x00000f02
  01-28 12:40:57.277  5263  5737 E CRASH   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
  01-28 12:40:57.277  5263  5737 E CRASH   : Version '2020.2.1f1 (270dd8c3da1c)', Build type 'Release', Scripting Backend 'il2cpp', CPU 'armeabi-v7a'
  01-28 12:40:57.277  5263  5737 E CRASH   : Build fingerprint: 'Allwinner/t1_e1111/e1111:6.0.1/MMB29M/20200109:eng/test-keys'
  01-28 12:40:57.277  5263  5737 E CRASH   : Revision: '0'
  01-28 12:40:57.277  5263  5737 E CRASH   : ABI: 'arm'
  01-28 12:40:57.277  5263  5737 E CRASH   : Timestamp: 2021-01-28 12:40:57+0100
  01-28 12:40:57.277  5263  5737 E CRASH   : pid: 5263, tid: 5737, name: Thread-254  &gt;&gt;&gt; com.game.test &lt;&lt;&lt;
  01-28 12:40:57.277  5263  5737 E CRASH   : uid: 10038
  01-28 12:40:57.277  5263  5737 E CRASH   : signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0x9f891034
  01-28 12:40:57.277  5263  5737 E CRASH   :     r0  fffffe04  r1  9f890e39  r2  00000000  r3  10000002
  01-28 12:40:57.277  5263  5737 E CRASH   :     r4  a2746e28  r5  9af28000  r6  00000000  r7  9f890e3c
  01-28 12:40:57.277  5263  5737 E CRASH   :     r8  92f11508  r9  9f89102c  r10 00000020  r11 92ab9eb0
  01-28 12:40:57.277  5263  5737 E CRASH   :     ip  92f0dca0  sp  92ab9e38  lr  8c3c46ed  pc  a0b48454
  01-28 12:40:57.277  5263  5737 E CRASH   :
  01-28 12:40:57.277  5263  5737 E CRASH   : backtrace:
  01-28 12:40:57.277  5263  5737 E CRASH   :       #00 pc 00214454  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.278  5263  5737 E CRASH   :       #01 pc 002103a4  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.278  5263  5737 E CRASH   :       #02 pc 00210094  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.278  5263  5737 E CRASH   :       #03 pc 0021aadc  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.278  5263  5737 E CRASH   :       #04 pc 0021ac10  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.278  5263  5737 E CRASH   :       #05 pc 0022d134  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.278  5263  5737 E CRASH   :       #06 pc 001fa510  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.279  5263  5737 E CRASH   :       #07 pc 001f92b4  /data/app/com.game.test-1/lib/arm/libil2cpp.so (BuildId: 8661ed98f50d30bd9dccc6724b2d8ce750125c)
  01-28 12:40:57.279  5263  5737 E CRASH   :       #08 pc 001bfb13  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.279  5263  5737 E CRASH   :       #09 pc 000d17bd  /data/app/com.game.test-1/lib/arm/libunity.so (BuildId: a35c8e4b1671f4c94678437952705f4cc95b4cb7)
  01-28 12:40:57.279  5263  5737 E CRASH   :       #10 pc 0005b573  /data/app/com.game.test-1/oat/arm/base.odex
  </code></pre>
  <p>Checking addresses using addr2line tool gives below:</p>
  <pre><code>01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0xcd1b8(Native Method)   void std::__ndk1::__tree_remove&lt;std::__ndk1::__tree_node_base&lt;void*&gt;*&gt;(std::__ndk1::__tree_node_base&lt;void*&gt;*, std::__ndk1::__tree_node_base&lt;void*&gt;*)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x1047fd(Native Method)  std::__ndk1::__tree&lt;DelayedCallManager::Callback, std::__ndk1::less&lt;DelayedCallManager::Callback&gt;, memory_pool&lt;DelayedCallManager::Callback&gt; &gt;::erase(std::__ndk1::__tree_const_iterator&lt;DelayedCallManager::Callback, std::__ndk1::__tree_node&lt;DelayedCallManager::Callback, void*&gt;*, int&gt;)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x103083(Native Method)  DelayedCallManager::Update(int)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x156493(Native Method)  ExecutePlayerLoop(NativePlayerLoopSystem*)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x1564af(Native Method)  ExecutePlayerLoop(NativePlayerLoopSystem*)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x156649(Native Method)  PlayerLoop()
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x21612b(Native Method)  UnityPlayerLoop()
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at libunity.0x22508d(Native Method)  nativeRender(_JNIEnv*, _jobject*)
  01-28 12:40:57.171  5263  5291 E AndroidRuntime:        at base.0x896b9(Native Method)
      
  </code></pre>