# Generating dll while UE4 editor is opened **URL:** \ **Category:** Platform & Builds\ **Tags:** c-build, unreal-engine, build-failed, question\ **Created:** [February 10, 2017, 3:34pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546 "2017-02-10T15:34:00Z")\ **Posts on this page:** 16\ **Page:** 3
**Author:** ![anonymous\_user\_8977fd73](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_8977fd73](https://forums.unrealengine.com/u/anonymous_user_8977fd73)\ **Post date:** [April 18, 2017, 7:53am UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/41 "2017-04-18T07:53:09Z")
I wasn’t able to upload it here, cause it’s too big ( 20mb ), so I put it on mega.nz `https://mega.nz/#!odZxRDST!GjPPGVl79_daR2A5q7aewrMjvXv_R8XpsEb1M_fzSK4` What I did was: 1. Opening 4.14 project in 4.15 ( just to be sure ). 2. Added fmod 3. Added custom actor class 4. Included some fmod header file 5. Called some random fmod static function. 6. Hot reload doesnt work after that. ---
**Author:** ![Khannarc](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Khannarc](https://forums.unrealengine.com/u/Khannarc)\ **Post date:** [April 19, 2017, 9:40am UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/42 "2017-04-19T09:40:45Z")
I think I have some similar issue going on with my project. I started working with the spine plugin for ue4 (skeletal 2D animsation plugin) and it worked perfectly fine until I tired to package my project yesterday. I had some errors showing up that required me to update my plugin because they were using editor-only classes in the first version. However, after updating the plugin UE4 required me to perform a rebuild for two .dll involved in the plugin. The automatic rebuild failed and asked me to perform a manual rebuild from source. When using the rebuild solution tool from VS2015 pro it comes up with an error such as "failed to produce item : “Project”/…/“Plugin.lib”. I lack any programming skill so my project is full blueprint and to be honest I don’t understand like half the stuff that is going on in this thread. Yet it would be awesome is a solution could be released for this plugin packaging issue. Best regards, Thom ---
**Author:** ![anonymous\_user\_8977fd73](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_8977fd73](https://forums.unrealengine.com/u/anonymous_user_8977fd73)\ **Post date:** [April 25, 2017, 10:05am UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/43 "2017-04-25T10:05:02Z")
Somebody is/will be working on that? When should we expect any news? ---
**Author:** ![anonymous\_user\_b666e59e](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_b666e59e](https://forums.unrealengine.com/u/anonymous_user_b666e59e)\ **Post date:** [April 25, 2017, 9:32pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/44 "2017-04-25T21:32:53Z")
Hi Krzysiek\_TATE, Thank you for the sample project that you provided. That got me started in the right direction, and I believe I am now able to reliably create a test project that shows the issue that you are still having. I have some additional tests that I want to run on this in the morning, but it looks like this may have already been corrected in our latest internal version of the Engine. I want to see if I can track down when this was corrected. ---
**Author:** ![anonymous\_user\_b666e59e](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_b666e59e](https://forums.unrealengine.com/u/anonymous_user_b666e59e)\ **Post date:** [April 26, 2017, 8:16pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/45 "2017-04-26T20:16:49Z")
Hello everyone, I was unable to determine exactly what change resolved the issue internally, but I was able to confirm that it appears to be working again. The test case that I was able to create with Krzysiek\_TATE’s help worked fine in 4.14.3, then failed to hot reload successfully in 4.15.1. It still seems to be failing the same way in 4.16, but it is working again in the Master branch. If any of you that have been seeing this ongoing hot reload issue occur have built the Engine from source code and don’t mind building the Engine from the Master branch, could you check and see if your hot reload issues are resolved there as well? I am hoping that the test case I was able to put together will cover any outstanding hot reload issues, but I can’t confirm that without your help. ---
**Author:** ![Flash7](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Flash7](https://forums.unrealengine.com/u/Flash7)\ **Post date:** [May 13, 2017, 12:30am UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/46 "2017-05-13T00:30:29Z")
4.16.0.p3 - it is still happening… I updated to VS2017 - the same result. We do not use any plug-ins. ---
**Author:** ![anonymous\_user\_b666e59e](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_b666e59e](https://forums.unrealengine.com/u/anonymous_user_b666e59e)\ **Post date:** [May 16, 2017, 1:36pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/47 "2017-05-16T13:36:04Z")
Hi Flash7, I have not been able to reproduce any of the previous Hot Reload issues in 4.16. Do you see the same results in a new test project with minimal assets? ---
**Author:** ![Flash7](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Flash7](https://forums.unrealengine.com/u/Flash7)\ **Post date:** [May 16, 2017, 2:08pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/48 "2017-05-16T14:08:59Z")
No, I can’t. It looks like it is happening with larger projects. But this is what I noticed. Even though it gave me this error: " -waitmutex" exited with code 5. Please verify that you have sufficient rights to run this command." DLL still reloaded and I see my changes in the editor. ---
**Author:** ![Akihiro.Kayama](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Akihiro.Kayama](https://forums.unrealengine.com/u/Akihiro.Kayama)\ **Post date:** [May 16, 2017, 2:27pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/49 "2017-05-16T14:27:31Z")
Here is my reproducible step: - unzip attached TemplateCopy.zip (I attached to the newest comment of [UDN thread](https://udn.unrealengine.com/questions/319627/uworldspawnactor-with-template-parameter-causes-cr.html), it is \>5MB so I can’t attach here) - switch engine version of TemplateCopy.uproject to github 4.16 branch workingcopy and generate TemplateCopy.sln - open TemplateCopy.sln with VS2015 Update 3 (all below steps are with VS) - Build TemplateCopy project - Start (without Debugging) TemplateCopy project - Open Source/TemplateCopy/MyBlueprintFunctionLibrary.cpp - Add a blank line - build project - (successfully built and Hot Reloaded) - Add more blank line - build project again - (then build fails) I tested with latest github 4.16 branch(until commit cef308c8aeebe56e97f2a77f7492dad6b0e4ac5c). ---
**Author:** ![anonymous\_user\_b666e59e](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_b666e59e](https://forums.unrealengine.com/u/anonymous_user_b666e59e)\ **Post date:** [May 16, 2017, 9:06pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/50 "2017-05-16T21:06:47Z")
Hi Akihiro Kayama, Thank you for the additional information. With that, I was able to determine what I had been missing. I had previously been testing 4.15 projects in 4.15 and 4.16 projects in 4.16, but I had not upgraded a project from 4.15 to 4.16. That appears to bring this build failure back again. I have entered [UE-45108](https://issues.unrealengine.com/issue/UE-45108) with what I observed happening in projects that had been upgraded to 4.16 instead of created in that version. ---
**Author:** ![ms.coding](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ms.coding](https://forums.unrealengine.com/u/ms.coding)\ **Post date:** [May 29, 2017, 9:16pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/51 "2017-05-29T21:16:40Z")
I have the same problem with a freshly installed Unreal Engine 4.16.0 and Visual Studio 2017. I used IncrediBuild, thought that was the problem, deinstalled it, restarted windows, compiled the project again while it was open in UnrealEd and it compiled flawlessly. But only once, after that it failed everytime. I get always the error messages: - Severity Error Failed to produce item: …Intermediate\Build\Win64\UE4Editor\Development\UE4Editor-MyProject-9840.lib …\ProjectFiles\ERROR 1 - Error MSB3075 The command ““C:\Program Files\Epic Games\UE\_4.16\Engine\Build\BatchFiles\Build.bat” MyProjectEditor Win64 Development “…\MyProject.uproject” -waitmutex” exited with code 5. Please verify that you have sufficient rights to run this command. …VCTargets\Microsoft.MakeFile.Targets 44 The interesting part: It reloads everytime successfully in UnrealEd, I can play-test the changes without problems. UnrealEd informs me correctly about the Hot reload completion and after that I can test them. ---
**Author:** ![kaitorched](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@kaitorched](https://forums.unrealengine.com/u/kaitorched)\ **Post date:** [June 5, 2017, 10:50am UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/52 "2017-06-05T10:50:49Z")
I’m having the same issues here. VS 2017 with 4.16 and a newly created 4.16 project… ---
**Author:** ![emjaymeow](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@emjaymeow](https://forums.unrealengine.com/u/emjaymeow)\ **Post date:** [June 5, 2017, 12:11pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/53 "2017-06-05T12:11:32Z")
Same for me with VS15 with 4.16 ---
**Author:** ![anonymous\_user\_a86583dd](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_a86583dd](https://forums.unrealengine.com/u/anonymous_user_a86583dd)\ **Post date:** [June 17, 2017, 9:59am UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/54 "2017-06-17T09:59:36Z")
Still Happens in 4.16.1 ---
**Author:** ![Langerz82](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Langerz82](https://forums.unrealengine.com/u/Langerz82)\ **Post date:** [June 6, 2018, 11:16pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/55 "2018-06-06T23:16:49Z")
I had a similar error and fixed it by: 1. Making sure you have Automation Tool compiled. 2. Copy AgentInterface.dll from Engine/Binaries/.DotNET to Engine/Binaries/Win64. 3. Make sure you have UnrealLightMass.exe added to trusted applications on your Firewall. Hope this helps somebody. ---
**Author:** ![Langerz82](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Langerz82](https://forums.unrealengine.com/u/Langerz82)\ **Post date:** [June 6, 2018, 11:17pm UTC](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546/56 "2018-06-06T23:17:26Z")
I had a similar error and fixed it by: 1. Making sure you have Automation Tool compiled. 2. Copy AgentInterface.dll from Engine/Binaries/.DotNET to Engine/Binaries/Win64. 3. Make sure you have UnrealLightMass.exe added to trusted applications on your Firewall. Hope this helps somebody. [Previous page](https://forums.unrealengine.com/t/generating-dll-while-ue4-editor-is-opened/384546.md?page=2)