Not the worst thing in the world since I can just edit the config, but I figured I'd report it upstream.

Process: vendettaclient [4262]
Path: /Applications/Vendetta.app/vendettaclient.app/Contents/MacOS/vendettaclient
Identifier: com.guildsoftware.vendettaclient
Version: 1.8.497 (1.8.497)
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: vendettaclient [4262]
User ID: 501

Date/Time: 2020-05-29 16:39:53.885 -0700
OS Version: Mac OS X 10.15.5 (19F96)
Report Version: 12
Anonymous UUID: 5115F354-A913-C824-9E00-510A3EBF0A5A

Time Awake Since Boot: 9400 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:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'fullscreen presentation options must include NSApplicationPresentationFullScreen'
abort() called
terminating with uncaught exception of type NSException

Application Specific Backtrace 1:
0 CoreFoundation 0x00007fff36fb5be7 __exceptionPreprocess + 250
1 libobjc.A.dylib 0x00007fff6fd8d5bf objc_exception_throw + 48
2 CoreFoundation 0x00007fff36fded98 +[NSException raise:format:arguments:] + 88
3 Foundation 0x00007fff396cde9d -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191
4 AppKit 0x00007fff3463548b -[_NSWindowFullScreenContentController initWithWindow:] + 360
5 AppKit 0x00007fff34c9b09a -[NSWindow(NSFullScreen) _createFullScreenContentControllerIfNeeded] + 65
6 AppKit 0x00007fff346e583d -[_NSWindowEnterFullScreenTransitionController start] + 60
7 AppKit 0x00007fff34c584c3 -[_NSFullScreenSpace(Transitions) startTransition:] + 133
8 opengl4.dylib 0x0000000105438ad5 -[GLFWApplicationDelegate syncFullScreenState] + 85