Returning to 4.15 from 4.16 is "bumpy"

Development Platform & Builds
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1

Returning to 4.15 proved bumpy. The C++ (my code) wouldn’t build - a problem in the toolchain - right click option to build the xcode workspace not working and the project wouldn’t rebuild my dylib on editor load. Verify project didn’t work but I got up and running by removing 4.15 completely and reinstalling.

Should have kept the logs, but it was late…

2

Hey -

I’m not sure I follow what’s happening in this instance. Are you referring to opening a project in the 4.16 preview and then running another project back in 4.15? Did you try to convert a 4.16 project backward to 4.15? If possible, please provide repro steps of what you did to help me test the behavior on my end.

3

Hi ,

On Mac,

  1. Convert project containing C++ to 4.16. Run it (means rebuilding dylibs).
  2. Convert the project back to 4.15
  3. Try opening the editor.

At this point I got asked if I want to rebuild the project (project files are out of date or created with a different version) but when I accepted that option it failed and told me to recompile manually.

Right clicking on the uproject to generate the xcode project failed to find the build tool.

A restart didn’t help, nor did verifying the engine (4.15) from the launcher, nor removing 4.16. What helped was removing 4.15 and reinstalling it.

4

Right click on uproject and “Switch Engine Version”. I didn’t create a copy. To get back I did the same (right click, switch version, set version to 4.15).

5

How are you converting the project? If you choose the “Open a Copy” option, it should create a second project so that you have the original 4.15 project and the copied 4.16 project. If you choose the “Convert in Place” option, the project cannot then be opened in 4.15 through the project browser as it is associated with a newer engine. This is the expected behavior in each case.

6

Here are the errors I get the I switch version back to 4.15 and try to generate the xcode project.

Last login: Wed May  3 23:43:58 on ttys001
MacMini:~ thomasshepherd$ cd "/Users/Shared/Epic Games/UE_4.15/Engine/Build/BatchFiles/Mac" 
MacMini:Mac thomasshepherd$  sh "/Users/Shared/Epic Games/UE_4.15/Engine/Build/BatchFiles/Mac/GenerateProjectFiles.sh" -project="/Users/thomasshepherd/MM/MM_04.uproject" -game

Setting up Unreal Engine 4 project files...

Setting up Mono
/Users/Shared/Epic Games/UE_4.15/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.5/Microsoft.CSharp.targets: error : Error executing tool '/Users/Shared/Epic Games/UE_4.15/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.5/mcs.exe': ApplicationName='/Users/Shared/Epic Games/UE_4.15/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.5/mcs.exe', CommandLine='/noconfig @/var/folders/sq/htrkqyts4dsg0n06cnrsklrc0000gn/T/tmp3e8253c9.tmp', CurrentDirectory='/Users/Shared/Epic Games/UE_4.15/Engine/Source/Programs/DotNETCommon/DotNETUtilities', Native error= Cannot find the specified file
Discovering modules, targets and source code for project...
* Assertion at loader.c:572, condition `!mono_loader_get_last_error ()' not met

Stacktrace:

  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) System.Reflection.MonoCMethod.InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&) <0xffffffff>
* Assertion at class.c:5748, condition `!mono_loader_get_last_error ()' not met

/Users/Shared/Epic Games/UE_4.15/Engine/Build/BatchFiles/Mac/GenerateProjectFiles.sh: line 26: 53219 Abort trap: 6           mono ../../../Binaries/DotNET/UnrealBuildTool.exe -XcodeProjectFile "$@"
MacMini:Mac thomasshepherd$
7

And here is the successful project generation output, after removing 4.15.2 and reinstalling it.

Last login: Thu May  4 08:43:29 on ttys000
MacMini:~ thomasshepherd$ cd "/Users/Shared/Epic Games/UE_4.15/Engine/Build/BatchFiles/Mac" 
MacMini:Mac thomasshepherd$  sh "/Users/Shared/Epic Games/UE_4.15/Engine/Build/BatchFiles/Mac/GenerateProjectFiles.sh" -project="/Users/thomasshepherd/MM/MM_04.uproject" -game

Setting up Unreal Engine 4 project files...

Setting up Mono
/Users/Shared/Epic Games/UE_4.15/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.5/Microsoft.CSharp.targets: error : Error executing tool '/Users/Shared/Epic Games/UE_4.15/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.5/mcs.exe': ApplicationName='/Users/Shared/Epic Games/UE_4.15/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.5/mcs.exe', CommandLine='/noconfig @/var/folders/sq/htrkqyts4dsg0n06cnrsklrc0000gn/T/tmp23f02041.tmp', CurrentDirectory='/Users/Shared/Epic Games/UE_4.15/Engine/Source/Programs/DotNETCommon/DotNETUtilities', Native error= Cannot find the specified file
Discovering modules, targets and source code for project...
Generating data for project indexing... 100%
Writing project files... 100%
MacMini:Mac thomasshepherd$
8

Hey -

I did run into an issue where upgrading the project to 4.16 would require a rebuild of the code inside of the IDE which was not necessary for converting a project to 4.15. This behavior has been reported here for investigation: Unreal Engine Issues and Bug Tracker (UE-44695) . When converting a project from 4.16 back to 4.15 however, I did not have any issues and the project was able to open immediately after using “Switch Engine Version”.

Cheers

9

Odd - I’ve had this behavior 2/2. The computer (MAC) was setup last week and 4.15 was the first version installed on it.

The problem seems to be with the engine installation rather than the project as when I reinstall 4.15 to get it working again I don’t change anything in my project directory.

Thanks for looking into it, I’m going to ignore it for now as bigger fish to fry in 4.15 / 4.16.