Whenever I try to start the manager, if I have managed to manually create a managed install (as the download/import process is separately broken) or if I have not deleted the modpacks.json file, the app immediately crashes.
It appears that you are running into the 'only main thread does UI' limitation placed on cocoa apps, but I don't know why this is only an issue with a loaded factorio instance or modpacks file.
willcharlton@Wills-MacBook-Pro .modmyfactorygui % /Users/willcharlton/Downloads/4/ModMyFactoryGUI run -v
[23:25:07 INF] Operating system: Darwin 21.2.0 Darwin Kernel Version 21.2.0: Sun Nov 28 20:28:54 PST 2021; root:xnu-8019.61.5~1/RELEASE_X86_64
[23:25:07 INF] Runtime: .NET 5.0.5
[23:25:08 INF] GUI version: 4.3.0.34-beta
[23:25:08 INF] Using ModMyFactory v1.4.0.75
[23:25:08 INF] Using ModMyFactory.BaseTypes v1.2.1.23
[23:25:08 INF] Using ModMyFactory.Export v1.4.0.29
[23:25:08 INF] Using ModMyFactory.Localization v1.1.0.9-alpha
[23:25:08 INF] Using ModMyFactory.ModSettings v1.2.0.21-alpha
[23:25:08 INF] Using ModMyFactory.WebApi v1.2.0.34
[23:25:08 INF] Using ModMyFactory.Win32 v1.1.0.15
[23:25:08 VRB] Application directory: /Users/willcharlton/Downloads/4
[23:25:08 VRB] Data directory: /Users/willcharlton/.modmyfactorygui
[23:25:08 DBG] Settings loaded:
factorio_location: #appdata
mod_location: #appdata
language: en
theme: BaseLight
update_on_startup: True
update_prerelease: False
window_restore_state: 100;72;2256;1167
manager_grid_length_1: 1*
manager_grid_length_2: 1*
online_grid_length_1: 1*
online_grid_length_2: 1*
online_sub_grid_length_1: 1*
online_sub_grid_length_2: 1*
window_maximized: False
[23:25:08 VRB] Unable to load Factorio Steam instance
[23:25:08 VRB] Successfully loaded managed Factorio instance from 'someFolder'
[23:25:08 VRB] No mopack file found, skipping import
[23:25:08 ERR] Application crashed
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.InvalidOperationException: Call from invalid thread
at Avalonia.Threading.Dispatcher.VerifyAccess()
at Avalonia.AvaloniaObject.VerifyAccess()
at Avalonia.AvaloniaObject..ctor()
at Avalonia.Application..ctor()
at ModMyFactoryGUI.App..ctor() in C:\projects\modmyfactory-gui\ModMyFactoryGUI\App.xaml.cs:line 47
--- End of inner exception stack trace ---
at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean wrapExceptions, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& hasNoDefaultCtor)
at System.RuntimeType.CreateInstanceDefaultCtorSlow(Boolean publicOnly, Boolean wrapExceptions, Boolean fillCache)
at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, Boolean wrapExceptions)
at System.Activator.CreateInstance[T]()
at Avalonia.Controls.AppBuilderBase`1.<>c__45`1.<Configure>b__45_0()
at Avalonia.Controls.AppBuilderBase`1.Setup()
at Avalonia.Controls.AppBuilderBase`1.SetupWithLifetime(IApplicationLifetime lifetime)
at Avalonia.ClassicDesktopStyleApplicationLifetimeExtensions.StartWithClassicDesktopLifetime[T](T builder, String[] args, ShutdownMode shutdownMode)
at ModMyFactoryGUI.Program.StartAppAsync(String[] args, RunOptions options) in C:\projects\modmyfactory-gui\ModMyFactoryGUI\Program.cs:line 378
[23:25:08 INF] Saving settings...
[23:25:08 DBG] Settings saved to '/Users/willcharlton/.modmyfactorygui/settings.json'
[23:25:08 INF] Shutting down