This bug looks like it might be a tricky one to repro. Working on uploading a project to repro in properly.

It seems to happen only when using .NET 4.6

Regression introduced on 2017.3.0b7. Not sure on 'true' impact on users (not repro'ed by anyone else I know), but could be because of specific features I am using that they are not (e.g. TextMesh Pro Input Field's). If this is an issue with TMPro, please accept my apologies and reassign away!

Having a peek at the log seems like a missing function or something?

There is a separate parsing error in the crash analyser, preventing the crash dump to show up there. Pasting from Editor.log:

========== OUTPUTING STACK TRACE ==================

0x00007FFB77C0C676 (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\metadata\class.c:4877] mono_class_init
0x00007FFB77C05BC2 (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\metadata\class.c:2945] collect_implemented_interfaces_aux
0x00007FFB77C1158F (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\metadata\class.c:4095] mono_class_setup_vtable_general
0x00007FFB77C114AE (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\metadata\class.c:3630] mono_class_setup_vtable_full
0x00007FFB77C0B7BB (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\metadata\class.c:2540] mono_class_get_vtable_entry
0x00007FFB77AB2779 (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\mini\mini-trampolines.c:903] mono_vcall_trampoline
ERROR: SymGetSymFromAddr64, GetLastError: 'The specified module could not be found.' (Address: 0000000010D41838)
ERROR: SymGetModuleInfo64, GetLastError: 'A dynamic link library (DLL) initialization routine failed.' (Address: 0000000010D41838)
0x0000000010D41838 ((<unknown>)) (function-name not available)
0x0000000057A047EC (Mono JIT Code) System.Collections.Generic.Stack`1<T_REF>:Push (T_REF)
0x0000000057A04460 (Mono JIT Code) [C:\buildslave\unity\build\Extensions\guisystem\UnityEngine.UI\UI\Core\Utility\ObjectPool.cs:46] UnityEngine.UI.ObjectPool`1<T_REF>:Release (T_REF)
0x00000000560B5C42 (Mono JIT Code) [C:\buildslave\unity\build\Extensions\guisystem\UnityEngine.UI\UI\Core\Utility\ListPool.cs:20] UnityEngine.UI.ListPool`1<UnityEngine.Vector3>:Release (System.Collections.Generic.List`1<UnityEngine.Vector3>)
0x00000000560B5805 (Mono JIT Code) [C:\buildslave\unity\build\Extensions\guisystem\UnityEngine.UI\UI\Core\Utility\VertexHelper.cs:105] UnityEngine.UI.VertexHelper:Dispose ()
0x00000000560B5541 (Mono JIT Code) TMPro.TMP_InputField:OnFillVBO (UnityEngine.Mesh)
0x00000000560B47AD (Mono JIT Code) TMPro.TMP_InputField:UpdateGeometry ()
0x00000000560A3A71 (Mono JIT Code) TMPro.TMP_InputField:Rebuild (UnityEngine.UI.CanvasUpdate)
0x0000000055F5CDD9 (Mono JIT Code) [C:\buildslave\unity\build\Extensions\guisystem\UnityEngine.UI\UI\Core\CanvasUpdateRegistry.cs:151] UnityEngine.UI.CanvasUpdateRegistry:PerformUpdate ()
0x0000000055F5C1ED (Mono JIT Code) [C:\buildslave\unity\build\artifacts\generated\common\modules\UI\UICanvasBindings.gen.cs:240] UnityEngine.Canvas:SendWillRenderCanvases ()
0x0000000055F5C0E9 (Mono JIT Code) [C:\buildslave\unity\build\artifacts\generated\common\modules\UI\UICanvasBindings.gen.cs:241] UnityEngine.Canvas:ForceUpdateCanvases ()
0x0000000055F5C016 (Mono JIT Code) [C:\buildslave\unity\build\Extensions\guisystem\UnityEngine.UI\UI\Core\ScrollRect.cs:259] UnityEngine.UI.ScrollRect:EnsureLayoutHasRebuilt ()
0x0000000055F5A218 (Mono JIT Code) [C:\buildslave\unity\build\Extensions\guisystem\UnityEngine.UI\UI\Core\ScrollRect.cs:382] UnityEngine.UI.ScrollRect:LateUpdate ()
0x00000000591504B4 (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void__this__ (object,intptr,intptr,intptr)
0x00007FFB77A1437A (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\mini\mini-runtime.c:2620] mono_jit_runtime_invoke
0x00007FFB77C18E87 (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\metadata\object.c:2853] do_runtime_invoke
0x00007FFB77C2188F (mono-2.0-bdwgc) [c:\buildslave\mono\build\mono\metadata\object.c:2905] mono_runtime_invoke
0x0000000140A2C47C (Unity) scripting_method_invoke
0x0000000140A1FE6A (Unity) ScriptingInvocation::Invoke
0x00000001409E2581 (Unity) MonoBehaviour::CallMethodIfAvailable
0x00000001409EC56F (Unity) MonoBehaviour::CallUpdateMethod
0x0000000140504B66 (Unity) BaseBehaviourManager::CommonUpdate<LateBehaviourManager>
0x0000000140504C38 (Unity) LateBehaviourManager::Update
0x000000014071EF53 (Unity) `InitPlayerLoopCallbacks'::`41'::PreLateUpdateScriptRunBehaviourLateUpdateRegistrator::Forward
0x000000014071C05E (Unity) PlayerLoop
0x00000001411DD625 (Unity) PlayerLoopController::UpdateScene
0x00000001411E7A0A (Unity) PlayerLoopController::EnterPlayMode
0x00000001411E8286 (Unity) PlayerLoopController::SetIsPlaying
0x00000001411E90D6 (Unity) Application::TickTimer
0x000000014140D79F (Unity) MainMessageLoop
0x000000014140F045 (Unity) WinMain
0x0000000141E5AAB8 (Unity) __tmainCRTStartup
0x00007FFBBBA62774 (KERNEL32) BaseThreadInitThunk
0x00007FFBBDE70D51 (ntdll) RtlUserThreadStart

========== END OF STACKTRACE ===========