I was working on a project in Unreal Engine, and everything went fine until yesterday when I (as usual) switched to Visual Studio to edit some code, but when I switched back to UE window, I noticed that the compile button on the top disappeared. I restarted UE and tried opening my project but all I got was a message box with the following text:
The following modules are missing or built with a different engine version:
UE4Editor-StayAlive.dll
Would you like to rebuild them now?
If I click No nothing happens, if I click Yes, it shows the progress bar and after that another error message
StayAlive could not be compiled. Try rebuilding from source manually.
Rebuilding the solution in Visual Studio doesnât help either.
I tried creating a new project in UE, but when I try to open it, it fails with the same error. I also reinstalled UE, but it also didnât help. What can I do to fix this problem?
I installed Unreal Engine 4.10.1 from Epic Games Launcher and I also use Visual Studio 2015 Community Edition which was installed when I first created a C++ project. I am able to open Content Examples project or a fresh project which was created from a blueprint template project, but the UE window doesnât have the Compile button on top (I guess because these projects donât have any C++ code).
The version from Help > About: 4.10.1-2791327+++depot+UE4-Releases+4.10
My project has also suddenly broken with the same error. I downloaded 4.10 on Tuesday and created a test c++ project based on the FPS template.
I have come back to it today and it builds fine in VS2015 Pro but then when it launches it says UE4Editor-Helicopter.dll is missing or build with different engine version.
It asks if you want to rebuilt. Press Yes and it says "Helicopter could not be compiled. Try rebuilding from the source manually.
Tried a clean/rebuild all of solution which was successful but still get same error.
When I run the DebugGame Editor configuration is VS (is it what you meant by run the editor in debug mode?), I get the same error, only difference is that the dll name is a little bit different (with -Win64-DebugGame appended).
What do I need to do after switching engine version? Do you mean I need to create the project using 4.10 and then switch it to 4.11 and open it in 4.11?
What you need to do to switch engine version is go into the folder that your project is located in. Then, find the .uproject file, right-click on it, and select Switch Engine Version. A window will appear asking you which version youâd like to switch to. Select either 4.10 or 4.11, and then attempt to open the project again.
It seems I finally fixed the problem when I added the Unreal Projects folder and folder with the engine (4.10 and 4.11) to antivirus exceptions. Iâm not sure what exactly my antivirus did, but now the editor window opens and I can edit my project. I have Avast in case it helps.
I also had this issue until I added my project folder to my Avast âFile System Shieldâ âExclusionsâ. I noticed that the .dll file was being successfully built by Unreal, then was immediately disappearing, and that was because Avast was deleting the .dll file.
I tried uninstalling Unreal 4.10.2 and reinstalling. I received an âinstalâ failed error. I restarted, and tried again and it verified, then installed with no error, but I still get the same dll issue.
fwiw - I didnât have VS installed and I wasnât using it until I read up on this issue.
Do you currently have Visual Studio 2015 installed? If so, did you ensure to enable to C++ content? The necessary C++ and Common Tools content does not come with VS by default, and you must manually enable it within the installer in order to get what you need to run the engine.