Issue 1:
Environment

Windows build number: 10.0.18975.0
Windows Terminal version: 0.5.2622.0

Steps to reproduce

Run wt.exe to start an instance of Windows Terminal

Press Ctrl-t 4 or 5 times to open a few tabs (running PowerShell)

In each tab, run dir c:\ -rec

Wait a few seconds, then click the 'x' on one of the tabs to close it while it is writing text to the console

Expected behavior

The tab closes.

Actual behavior

The terminal crashes with an Access Violation due to a null pointer dereference in TerminalControl!winrt::impl::consume_Windows_UI_Xaml_Controls_Primitives_IRangeBase<winrt::Windows::UI::Xaml::Controls::Primitives::ScrollBar>::Maximum

Notes

I can reproduce this consistently. Let me know if you would like a memory dump.

Here is a link to the feedback issue I opened:

https://aka.ms/AA65up1

Call stack

rax=0000d0e9f60fae3a rbx=00000000000002d6 rcx=0000000000000000
rdx=0000000000000000 rsi=00000000000002d6 rdi=000000000000001c
rip=00007ffd75b073d1 rsp=00000095845ff250 rbp=000001afa9234f70
r8=0000000010000000 r9=0000000000000000 r10=0000000000000000
r11=0000000000000246 r12=0000000000000000 r13=000000000000001c
r14=00007ffda8394d10 r15=0000000000000000
iopl=0 nv up ei pl zr na po nc
cs=0033 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010246
TerminalControl!winrt::impl::consume_Windows_UI_Xaml_Controls_Primitives_IRangeBase<winrt::Windows::UI::Xaml::Controls::Primitives::ScrollBar>::Maximum+0x51:
00007ffd`75b073d1 488b01 mov rax,qword ptr [rcx] ds:00000000`00000000=????????????????

Child-SP RetAddr Call Site
00 00000095`845ff250 00007ffd`75b1812c TerminalControl!winrt::impl::consume_Windows_UI_Xaml_Controls_Primitives_IRangeBase<winrt::Windows::UI::Xaml::Controls::Primitives::ScrollBar>::Maximum+0x51 [E:\BA\35\s\src\cascadia\TerminalControl\Generated Files\winrt\Windows.UI.Xaml.Controls.Primitives.h @ 2838]
01 (Inline Function) --------`-------- TerminalControl!winrt::Microsoft::Terminal::TerminalControl::implementation::TermControl::_ScrollbarUpdater+0x14 [E:\BA\35\s\src\cascadia\TerminalControl\TermControl.cpp @ 1373]
02 (Inline Function) --------`-------- TerminalControl!winrt::Microsoft::Terminal::TerminalControl::implementation::TermControl::_TerminalScrollPositionChanged::__l2::<lambda_d4673cfb40ab3bbddd63d78386fc20ac>::operator()+0x43 [E:\BA\35\s\src\cascadia\TerminalControl\TermControl.cpp @ 1396]
03 00000095`845ff2c0 00007ffd`9f91c471 TerminalControl!winrt::impl::delegate<winrt::Windows::UI::Core::DispatchedHandler,<lambda_d4673cfb40ab3bbddd63d78386fc20ac> >::Invoke+0x5c [E:\BA\35\s\src\cascadia\TerminalControl\Generated Files\winrt\windows.ui.core.h @ 1275]
04 (Inline Function) --------`-------- Windows_UI!Windows::UI::Core::CDispatcher::EnqueueAsyncWork::__l16::<lambda_59517943c03487243f9bea31c6c1a784>::operator()+0x67 [onecoreuap\windows\advcore\winrt\onecoreiwindow\corewindow\common\dispatcher.cpp @ 908]
05 00000095`845ff310 00007ffd`a8394d26 Windows_UI!Microsoft::WRL::Details::DelegateArgTraits<long (__cdecl Windows::System::IDispatcherQueueHandler::*)(void)>::DelegateInvokeHelper<Microsoft::WRL::Implements<Microsoft::WRL::RuntimeClassFlags<2>,Windows::System::IDispatcherQueueHandler,Microsoft::WRL::FtmBase>,<lambda_59517943c03487243f9bea31c6c1a784>,-1>::Invoke+0x71 [onecore\external\sdk\inc\wrl\event.h @ 245]
06 00000095`845ff340 00007ffd`a836423b CoreMessaging!Windows::System::DispatcherQueue::DeferInvokeCallback+0x16 [mincore\coreui\dev\dispatcherqueue\WrtDispatcherQueue.cpp @ 893]
07 00000095`845ff370 00007ffd`a8361d64 CoreMessaging!Microsoft__CoreUI__Dispatch__TimeoutHandler$CallbackThunk+0x11b [temp\42829c929effddb13f17f63c5ec49c58\Common__DllInterop.cpp @ 505]
08 (Inline Function) --------`-------- CoreMessaging!System::Action::Invoke+0x1a [mincore\cn\cnruntime\lib\fullstr\fre\objfre\amd64\CnRuntime\Common__Delegate.cpp @ 91]
09 00000095`845ff3f0 00007ffd`a83616fe CoreMessaging!Microsoft::CoreUI::Dispatch::DeferredCall::Callback_Dispatch+0x2c4 [mincore\CoreUI\Dev\System\Dispatch\DeferredCall.cs @ 62]
0a 00000095`845ff4b0 00007ffd`a8368d1a CoreMessaging!Microsoft::CoreUI::Dispatch::DeferredCallDispatcher::Callback_OnDispatch+0x15e [mincore\CoreUI\Dev\System\Dispatch\DeferredCallDispatcher.cs @ 337]
0b (Inline Function) --------`-------- CoreMessaging!Microsoft::CoreUI::Dispatch::Dispatcher::DispatchNextItem+0x685 [mincore\CoreUI\Dev\System\Dispatch\Dispatcher.cs @ 892]
0c (Inline Function) --------`-------- CoreMessaging!Microsoft::CoreUI::Dispatch::Dispatcher::Callback_DispatchLoop+0x7d7 [mincore\CoreUI\Dev\System\Dispatch\Dispatcher.cs @ 465]
0d 00000095`845ff520 00007ffd`a8367df6 CoreMessaging!Microsoft::CoreUI::Dispatch::EventLoop::Callback_RunCoreLoop+0xada [mincore\CoreUI\Dev\System\Dispatch\EventLoop.cs @ 779]
0e (Inline Function) --------`-------- CoreMessaging!Microsoft::CoreUI::Dispatch::UserAdapterBase::DrainCoreMessagingQueue+0x143 [mincore\CoreUI\Dev\System\Dispatch\UserAdapterBase.cs @ 674]
0f 00000095`845ff640 00007ffd`a83668d1 CoreMessaging!Microsoft::CoreUI::Dispatch::UserAdapter::OnUserDispatch+0x1d6 [mincore\CoreUI\Dev\System\Dispatch\minwin\UserAdapter.cs @ 224]
10 (Inline Function) --------`-------- CoreMessaging!Microsoft::CoreUI::Dispatch::UserAdapter::OnUserDispatchRaw+0x9c [mincore\CoreUI\Dev\System\Dispatch\minwin\UserAdapter.cs @ 153]
11 00000095`845ff730 00007ffd`a83666f3 CoreMessaging!Microsoft::CoreUI::Dispatch::UserAdapter_DoWork+0xf1 [mincore\CoreUI\Dev\System\Dispatch\minwin\UserAdapterN.cpp @ 424]
12 00000095`845ff810 00007ffd`ac99f903 CoreMessaging!Microsoft::CoreUI::Dispatch::UserAdapter_WindowProc+0xa3 [mincore\CoreUI\Dev\System\Dispatch\minwin\UserAdapterN.cpp @ 659]
13 00000095`845ff890 00007ffd`ac99f2ac USER32!UserCallWinProcCheckWow+0x4e3 [clientcore\windows\core\ntuser\client\clmsg.cxx @ 279]
14 00000095`845ffa20 00007ffd`ac9b4543 USER32!DispatchClientMessage+0x9c [clientcore\windows\core\ntuser\client\daytona\objfre\amd64\client.cxx @ 3444]
15 00000095`845ffa80 00007ffd`add30664 USER32!__fnDWORD+0x33 [onecoreuap\internal\windows\inc\ntuser\inc\ntcb.h @ 1214]
16 00000095`845ffae0 00007ffd`abc01104 ntdll!KiUserCallbackDispatcherContinue [minkernel\ntos\rtl\amd64\trampoln.asm @ 601]
17 00000095`845ffb68 00007ffd`ac9b54ee win32u!ZwUserGetMessage+0x14 [onecoreuap\windows\core\umode\moderncore\objfre\amd64\usrstubs.asm @ 190]
18 00000095`845ffb70 00007ff7`3bbe46c6 USER32!GetMessageW+0x2e [onecoreuap\internal\windows\inc\private\core\ntuser\client\ntcftxt.h @ 538]
19 00000095`845ffbd0 00007ff7`3bbecc42 WindowsTerminal!wWinMain+0x1c6 [E:\BA\35\s\src\cascadia\WindowsTerminal\main.cpp @ 150]
1a (Inline Function) --------`-------- WindowsTerminal!invoke_main+0x21 [d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl @ 118]
1b 00000095`845ffce0 00007ffd`aced7034 WindowsTerminal!__scrt_common_main_seh+0x106 [d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl @ 288]
1c 00000095`845ffd20 00007ffd`adcfb1b1 KERNEL32!BaseThreadInitThunk+0x14 [clientcore\base\win32\client\thread.c @ 64]
1d 00000095`845ffd50 00000000`00000000 ntdll!RtlUserThreadStart+0x21 [minkernel\ntdll\rtlstrt.c @ 1153]

Issue 2:
NOTE: This is different from, but may be related to, #2230

Environment

Windows build number: Microsoft Windows [Version 10.0.18362.175]
Windows Terminal version: 0.3.2142.0

Steps to reproduce

Open a new Windows Terminal instance

Open a second tab using either the "+" button

Close the new tab using CTRL+W, middle clicking the tab, or clicking the tab's "x"

Repeat steps 2-3 as fast as possible.

Expected behavior

Tabs continue to open and close.

Actual behavior

PowerShell - Most of the time, WT stops responding and interacting with it shows the "WindowsTerminal.exe is not responding" modal

CMD / WSL - WT stops responding for about 1 second and then exits (also happens for PowerShell sometimes)