Steps to reproduce:
1. Create and open new project
2. Press on collab drop down menu

Results: Editor crashes. Also reproducible when pressing Layers, Layout drop-down menus, Gizmo, Terrain's brush buttons.

Reproduced with: 2018.1.0b1 2017.3.0p1 2017.3.a6
Not reproducible with: 2017.3.0a5, 2017.2.1p1
Regression introduced in: 2017.3.0a6

Reproducible on: OSX 10.9.5 and 10.10.2
Not Reproducible on: OSX 10.11.2 and newer version

Stack Trace:
#0 0x007fff86d50097 in objc_msgSend
#1 0x007fff87ff8100 in -[NSWindow _close]
#2 0x0000012d8525c2 in (wrapper managed-to-native) UnityEditor.ContainerWindow:InternalClose () + 0xf2 (0x12d8524d0 0x12d8525f1) [0x14781f330 - Unity Child Domain]
#3 0x0000012d852442 in UnityEditor.ContainerWindow:Close () + 0xb2 (0x12d852390 0x12d8524a6) [0x14781f330 - Unity Child Domain]
#4 0x0000012d85234c in UnityEditor.TooltipView:Close () + 0xec (0x12d852260 0x12d852385) [0x14781f330 - Unity Child Domain]
#5 0x00000128b1cb56 in (wrapper runtime-invoke) object:runtime_invoke_void (object,intptr,intptr,intptr) + 0xf6 (0x128b1ca60 0x128b1cc89) [0x14781f330 - Unity Child Domain]
#6 0x000001470231ce in mono_get_runtime_build_info
#7 0x0000014714fab6 in mono_runtime_invoke
#8 0x00000100d1dbfa in mono_runtime_invoke_profiled(MonoMethod*, MonoObject*, void**, MonoException**, MonoClass*)
#9 0x00000101007fb9 in CallStaticMonoMethod(char const*, char const*, void**, ScriptingExceptionPtr*)
#10 0x00000101007f69 in CallStaticMonoMethod(char const*, char const*, void**)
#11 0x0000010190d2d2 in TooltipManager::Update()
#12 0x0000010199b2c7 in Application::TickTimer()
#13 0x007fff8cd8e714 in __NSFireTimer
#14 0x007fff92eb53e4 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
#15 0x007fff92eb4f1f in __CFRunLoopDoTimer
#16 0x007fff92f265aa in __CFRunLoopDoTimers
#17 0x007fff92e706a5 in __CFRunLoopRun
#18 0x007fff92e6fe75 in CFRunLoopRunSpecific
#19 0x007fff91cfba0d in RunCurrentEventLoopInMode
#20 0x007fff91cfb7b7 in ReceiveNextEventCommon
#21 0x007fff91cfb5bc in _BlockUntilNextEventMatchingListInModeWithFilter
#22 0x007fff87d8d24e in _DPSNextEvent
#23 0x007fff87d8c89b in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:]
#24 0x007fff87d8099c in -[NSApplication run]
#25 0x007fff87d6b783 in NSApplicationMain
#26 0x000001006d2807 in EditorMain(int, char const**)
#27 0x000001006d2c89 in main
#28 0x007fff8a5ed5fd in start