Another High Sierra crash?

Here’s another case my user-with-crash-problems sent me - my app is opening a window, and he’s one of two people reporting problems.

The window does crash some pictures in its Listbox.Paint event, but otherwise it’s nothing fancy.

The app is built in Xojo 2016r3, so it uses old-style graphics, not the modern ImageSets. Should I be looking at the multiple-of-fours issue?

Here’s the crash log, someday I’ll know enough to be able to figure these things out for myself, but in the meantime can anyone take a quick look and tell me what it looks like is causing the crash?

Any help would be greatly appreciated, thanks!

============================================

Process: Lightwright 6 [463]
Path: /Applications/Lightwright 6.app/Contents/MacOS/Lightwright 6
Identifier: com.mckernon.lightwright6
Version: 6.0.16 beta build 179 (6.0.16.2.179)
Code Type: X86 (Native)
Parent Process: ??? [1]
Responsible: Lightwright 6 [463]
User ID: 501

Date/Time: 2018-02-11 15:08:10.940 -0500
OS Version: Mac OS X 10.13.3 (17D47)
Report Version: 12
Bridge OS Version: 3.0 (14Y661)
Anonymous UUID: 12B5A55F-0E19-0C19-B9A9-0D1639F3C144

Time Awake Since Boot: 1700 seconds

System Integrity Protection: enabled

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY

Application Specific Information:
Assertion failed: (mach_vm_map(mach_task_self(), &address, size, 0, VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_MEMORY_COREGRAPHICS_BACKINGSTORES), port, 0, false, prot, prot, VM_INHERIT_SHARE) == KERN_SUCCESS), function backing_map, file /BuildRoot/Library/Caches/com.apple.xbs/Sources/SkyLight/SkyLight-312.23.4/SkyLight/Services/Windows/CGSBackingStore.c, line 191.

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 libsystem_kernel.dylib 0xa76fdeae __pthread_kill + 10
1 libsystem_pthread.dylib 0xa782f4c7 pthread_kill + 363
2 libsystem_c.dylib 0xa764dafe abort + 133
3 libsystem_c.dylib 0xa76180cd __assert_rtn + 305
4 com.apple.SkyLight 0xa48bd801 backing_map + 588
5 com.apple.SkyLight 0xa485cd13 lock_window_backing + 775
6 com.apple.SkyLight 0xa48885e2 SLSDeviceLock + 51
7 com.apple.AppKit 0x914f4db4 lock_device + 41
8 com.apple.AppKit 0x914cbad6 NSCGSWindowBackingStoreMark__block_invoke + 893
9 com.apple.AppKit 0x91497b98 NSCGSTransactionRunPreCommitActionsForOrder
+ 220
10 com.apple.AppKit 0x91497aac NSCGSTransactionRunPreCommitActions
+ 24
11 com.apple.AppKit 0x91497a85 __39+[_NSCGSTransaction currentTransaction]_block_invoke + 41
12 com.apple.QuartzCore 0x9c83acb9 CA::Transaction::run_commit_handlers(CATransactionPhase) + 45
13 com.apple.QuartzCore 0x9c83a260 CA::Context::commit_transaction(CA::Transaction*) + 1500
14 com.apple.QuartzCore 0x9c8399e3 CA::Transaction::commit() + 459
15 com.apple.AppKit 0x91c48577 __65+[CATransaction(NSCATransaction) NS_setFlushesWithDisplayRefresh]_block_invoke + 465
16 com.apple.CoreFoundation 0x93968316 _runLoopObserverWithBlockContext + 22
17 com.apple.CoreFoundation 0x93968026 CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION + 22
18 com.apple.CoreFoundation