# Plugin reload crash **URL:** \ **Category:** Plugins\ **Tags:** unreal-engine, crash, bug-report, Plugins, UE4, question, hot-reload\ **Created:** [January 25, 2016, 9:56am UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275 "2016-01-25T09:56:10Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![anonymous\_user\_7fb66735](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_7fb66735](https://forums.unrealengine.com/u/anonymous_user_7fb66735)\ **Post date:** [January 25, 2016, 9:56am UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275/1 "2016-01-25T09:56:10Z")
Hi, I’m currently exploring the making of plugins and I found a annoying crash when trying to change my plugin runtime. Reproduction steps: ``` Create a new c++ project from scratch Open Edit > Plugins Press New Plugin and select "Toolbar Button" Exit editor and recompile Open editor Change implementation of PluginButtonClicked, by adding a log or anything Open Window > Developer > Modules Click recompile of your toolbar button After recompile, press your toolbar button, notice that your added logic doesn't happen Open Window and the editor crashes with callstack ``` Unknown exception - code 00000001 (first/second chance not available) "Assertion failed: IsValid() [File:C:\Program Files\Epic Games\4.10\Engine\Source\Runtime\Core\Public\Templates\SharedPointer.h] [Line: 728] " ``` UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\misc\outputdevice.cpp:374] UE4Editor_MyToolbarButton_4667!TCommands::Get() [c:\program files\epic games\4.10\engine\source\runtime\slate\public\framework\commands\commands.h:61] UE4Editor_MyToolbarButton_4667!FMyToolbarButtonModule::AddMenuExtension() [c:\users\rannarem\documents\unreal projects\coolgameee\plugins\mytoolbarbutton\source\mytoolbarbutton\private\mytoolbarbutton.cpp:75] UE4Editor_MyToolbarButton_4667!TBaseRawMethodDelegateInstance<0,FMyToolbarButtonModule,void __cdecl(FMenuBuilder &__ptr64)>::ExecuteIfSafe() [c:\program files\epic games\4.10\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:582] UE4Editor_Slate!FExtender::Apply() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\multiboxextender.cpp:191] UE4Editor_Slate!FMenuBuilder::ApplyHook() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\multiboxbuilder.cpp:289] UE4Editor_Slate!FMenuBuilder::EndSection() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\multiboxbuilder.cpp:195] UE4Editor_MainFrame!FMainMenu::FillWindowMenu() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\mainframe\private\menus\mainmenu.cpp:284] UE4Editor_MainFrame!TBaseStaticDelegateInstance __cdecl(FMenuBuilder &__ptr64),TSharedRef,TSharedPtr >::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:854] UE4Editor_Slate!SMenuEntryBlock::MakeNewMenuWidget() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:1294] UE4Editor_Slate!TMemberFunctionCaller (__cdecl SMenuEntryBlock::*)(void)const__ptr64>::operator()<>() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstanceinterface_variadics.h:161] UE4Editor_Slate!TTupleImpl >::ApplyAfter_ExplicitReturnType,TMemberFunctionCaller (__cdecl SMenuEntryBlock::*)(void)const__ptr64> >() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\tuple.h:113] UE4Editor_Slate!TBaseSPMethodDelegateInstance<1,SMenuEntryBlock,0,TSharedRef __cdecl(void)>::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282] UE4Editor_Slate!TBaseDelegate >::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:440] UE4Editor_Slate!SMenuAnchor::SetIsOpen() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\widgets\input\smenuanchor.cpp:294] UE4Editor_Slate!SMenuEntryBlock::OnClicked() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:996] UE4Editor_Slate!SMenuEntryBlock::OnMenuItemButtonClicked() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:927] UE4Editor_Slate!TMemberFunctionCaller::operator()<>() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstanceinterface_variadics.h:161] UE4Editor_Slate!TTupleImpl >::ApplyAfter_ExplicitReturnType >() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\tuple.h:113] UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SMenuEntryBlock,0,FReply __cdecl(void)>::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282] UE4Editor_Slate!TBaseDelegate::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:440] UE4Editor_Slate!SButton::OnMouseButtonDown() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:180] UE4Editor_Slate!::operator()() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4196] UE4Editor_Slate!FEventRouter::Route >() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:214] UE4Editor_Slate!FSlateApplication::RoutePointerDownEvent() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4185] UE4Editor_Slate!FSlateApplication::ProcessMouseButtonDownEvent() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4143] UE4Editor_Slate!FSlateApplication::OnMouseDown() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4079] UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:1354] UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:1721] UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:719] UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:641] user32 user32 UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:884] UE4Editor!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\launchengineloop.cpp:2391] UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\launch.cpp:142] UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\windows\launchwindows.cpp:126] UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\windows\launchwindows.cpp:200] UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264] kernel32 ntdll ``` This is tested in 4.10.2 and 4.11.0 preview 3 Cheers, ---
**Author:** ![anonymous\_user\_2b03d27c](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_2b03d27c](https://forums.unrealengine.com/u/anonymous_user_2b03d27c)\ **Post date:** [January 25, 2016, 7:00pm UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275/2 "2016-01-25T19:00:49Z")
Hey MarkusRannare- I followed the steps listed but did not receive a crash when clicking the button. Are you using the engine from source code or the binary version from the Launcher? Can you post the log files from your crash as well? Cheers ---
**Author:** ![anonymous\_user\_7fb66735](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_7fb66735](https://forums.unrealengine.com/u/anonymous_user_7fb66735)\ **Post date:** [January 26, 2016, 8:31am UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275/3 "2016-01-26T08:31:10Z")
Hi , I’m running from Launcher version. And to clarify, by “Window” I mean the Window dropdown menu right beside “Edit” ( this is where the toolbar adds a menu extension ) This is also verified now on my computer at home running 4.10.2 with exact same crash. The log from 4.11 prev 3 is here: > **[Crashlog plugin reload - Pastebin.com](https://pastebin.com/wUDZCRus)** > > Pastebin.com is the number one paste tool since 2002. Pastebin is a website where you can store text online for a set period of time. PS: Important to actually change anything in a file before recompile (adding a newline is enough) Edit: I also noted now that I have developed another plugin in 4.10 where I register a hook on the right click menu using: GetAllLevelViewportContextMenuExtenders, it seems to crash when I open up the right click menu and showing the button after a recompile of the module ---
**Author:** ![anonymous\_user\_2b03d27c](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_2b03d27c](https://forums.unrealengine.com/u/anonymous_user_2b03d27c)\ **Post date:** [January 26, 2016, 6:58pm UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275/4 "2016-01-26T18:58:40Z")
After further testing I am still unable to reproduce the crash. Here are the steps I used to test: 1. Create a new project based on the Basic Code template 2. Edit-\>Plugins 3. Click the “New plugin” button and select Toolbar Button with a name of MyPlugin 4. Close the editor 5. In Visual Studio, Build the project to compile it. 6. Reopen the editor 7. In MyPlugin.cpp in Visual Studio- I added `UE_LOG(LogTemp, Warning, TEXT("Your message"));` at the beginning of `void FMyPluginModule::PluginButtonClicked()` 8. In the editor go to Windows-\>Developer Tools-\>Modules 9. Find MyPlugin and press the Recompile button 10. When the compile finishes, press teh toolbar button for MyPlugin When I click the toolbar button there is a prompt to add code to PluginButtonClicked() however the editor does not crash. If I restart the project at this point then clicking the toolbar button gives the same prompt and will show the “Your Message” text as a warning in the output log. ---
**Author:** ![anonymous\_user\_7fb66735](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_7fb66735](https://forums.unrealengine.com/u/anonymous_user_7fb66735)\ **Post date:** [January 27, 2016, 7:59am UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275/5 "2016-01-27T07:59:17Z")
I’m sorry, I guess my reproduction steps was not detailed enough. Step 10 should be: Open the “Window” dropdown, that is, the menu to the right of the “Edit” dropdown. See attached image for what dropdown menu I mean. ![76183-editorcrash.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/9/a/f/9afe7fa056076f8be967c5e93d9b81f8019f9cb8.png) Thanks for keeping up with me here Daug. ---
**Author:** ![anonymous\_user\_2b03d27c](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_2b03d27c](https://forums.unrealengine.com/u/anonymous_user_2b03d27c)\ **Post date:** [January 27, 2016, 3:38pm UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275/6 "2016-01-27T15:38:16Z")
Hey - I missed that accessing the Window menu bar was part of the reproduction steps. I was able to reproduce the crash and have entered a bug report (UE-26081) for investigation. Cheers ---
**Author:** ![lazypenguin](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@lazypenguin](https://forums.unrealengine.com/u/lazypenguin)\ **Post date:** [September 21, 2019, 9:49am UTC](https://forums.unrealengine.com/t/plugin-reload-crash/345275/7 "2019-09-21T09:49:04Z")
This issue still exists in 4.22.1 (launcher version) but the bug report was closed. The issue can also be reproduced by `reloading` the module and not only when `recompiling`. I’ve added some code to my `Shutdown()` function to remove the `MenuExtender` but it doesn’t resolve the issue. **Issue** 1. Create plugin that uses a `MenuExtender` (e.g. default plugin example for nomad tab) 2. In `Window -> Developer Tools -> Modules` either `reload`, `unload` or `recompile` the plugin 3. Click the `Window` menu option from the main menu bar **Expected:** 4. Menu loads as normal (or in the case of `unload` without the plugin menu entry **Actual:** 5. Editor crashes **Fix attempts:** - Remove `MenuExtender` on shutdown **Crash** - Remove `MenuExtensions` from `MenuExtender` on shutdown **Crash** - Remove usage of `MenuExtender` entirely **No crash** Furthermore, this doesn’t seem to be an issue with `ToolbarExtensions` but there is still some unexpected behavior when removing a `ToolbarExtension` on `Shutdown()`. The icon is removed but the extension and button persist. I suspect this might be related to the issue (I.E. on unloading these plugin modules the toolbars/menus don’t get cleaned up properly). See attached image. ![287975-toolbarpluginreload.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/f/b/7fbc0dbdedd30d835b4a400c63efbdf0684d2a1f.png) **UE bug reports** - [Unreal Engine Issues and Bug Tracker (UE-26081)](https://issues.unrealengine.com/issue/UE-26081) - [Unreal Engine Issues and Bug Tracker (UE-66852)](https://issues.unrealengine.com/issue/UE-66852) **Attachments**