OS X Project Corruptions

I’m attempting to get started with UE4 to replace our Unity development. One reoccurring problem that has nagged me while attempting to learn UE4, is project corruptions. It seems to come out of nowhere. I will exit the editor with a working test or modded tutorial, and when I next load the project, it will be corrupted and must be reloaded from a backup (or just start over since all I’m doing is testing and learning the API). It doesn’t happen every time, but it’s frequently enough that it would be a showstopper if it’s a normal behavior. It is always accompanied by an error listing as below, seeming to point to the project having inappropriate pointers and paths to my stuff. I am avoiding Xcode right now and use MacVim to do my coding, and the project Compile to compile it, which seems to work fine, though I was wondering if that could be the source of the issue. Actually though, I have no idea. It has happened on the ShooterGame twice or more, on the Vehicle game once, and on my tests from building wiki tutorial projects like FPSShooter (it’s happened a couple of times on this one). I’m concerned that the Mac version of the editor is fragile, but want to find out if it’s something I’m doing.

Has anyone else, using the editor under OS X 10.10, had such issues? Can they be fixed by hacking the project configuration files? Reloading projects minus recent changes would be a significant development stumbling block.

This is an example of the type errors I get in the Crash Reporter window only many more, I didn’t want to glut the post with the entire transcript (I send the crash reports but have no idea if anyone is looking at them). It shows 4.7, but has happened several times on 4.6.

I assume from no response, that this must not be a common problem, or (not surprisingly) fewer people are using OS X for development. If anyone does run into this, please contact me. I’m presently saving and exiting if I get more than an hour into development, then running a quick time machine so I have frequent progress backups.

I would be interested if anyone does know the secrets to correcting the project config files when a project shows corruptions, if any such correction exists.

Im struggling with this problem too. It crashes randomly in different cases even if i don’t recompile code at the moment (just tune material for example). The only way i can suggest is BootCamp/Win :frowning: Dunno how to solve it on Mac.

Make sure you’ve filed an Answerhub question about this - it’ll be assigned a bug number & be properly investigated. We’ll want you to add the project logs (~/Library/Logs, Hold Alt/Option & open Finder’s Go menu for quick access to ~/Library) & crash reports (~/Library/Preferences/UnrealEngine/Crashes). A run down of your Mac’s spec’s might also be helpful as would any steps you take that result in this problem occurring.

Have you tried deleting the following folders:


(DerivedDataCache may not exist).

I’ve found that, especially – but not only – in Blueprint-heavy projects under version control, sometimes Blueprint linking and other project state gets out of sync. For some reason, the Mac editor (at least prior to 4.7, which seems better) tends to crash as a result of these inconsistencies where the Windows version often will not.

I would not touch the config files unless you’re sure there’s a problem with them. I doubt your coprruption problems come from config files, and you could make things worse if you don’t know what you’re doing in there.

Once you get the project open, you may get compile errors reported despite not having changed previously functioning Blueprints. In those cases, open the offending blueprints and select “Refresh All Nodes” from the File menu with the node graph showing. If that option isn’t there, switch to another tab or window and then come back to the blueprint.

Finally, if you’re not on 4.7, move to 4.7 ASAP. It’s a much improved experience on the Mac in my experience. Much improved on Windows too, for that matter, but it seems to resolve some of the Mac-specific crashers related to blueprint state.

I began to have this problem again. It appears it was not related to blueprints or other assets, just C++ classes that I was actively involved in compiling in the previous session.

I was able to get around it, by deleting the numbered .dylib files in the project folder Binaries/Mac. Once I do that, I have had to open Xcode using the project’s .xcodeproj file in the root of the project file. Then I make an insignificant change to the class listed at the top of the dump, manually do a build, close Xcode, and the project will once again load and work.

This has been on 4.6. I imagine the above comment concerning 4.7 may be the real solution. Unfortunately, some of our model’s meshes, load sideways in 4.7, so I haven’t moved yet until that sorts itself out.

I can reproduce this on 4.7.5 mostly consistently. It appears to be a bug. If code is added to a class, it may, after testing successfully and then closing the project, cause the editor to get the type of error mentioned in the OP. The only solution is to remove the code, remove the dylib files, rebuilding in xcode, then reloading the editor. While the editor is running, it seems to accept code changes (which may have some disagreement in how things are to be done in unreal, just a guess) and work. But on closing, it can’t reload that project. It would seem that it has a bug only in that it should be rejecting the changes prior to testing, rather than allowing all to seem like it’s working. I’ve sent several reports when the error came up. I don’t know if developers monitor those or not.

I can recreate this by using creating a TArray of structs and adding dynamic entries from a working struct of the same type, but that is not what I originally was doing. Originally, very simple additions to classes were causing the issues. I may be doing something wrong in this particular code, but it seems odd that the Editor should crash when I try to reload it. I guess I will try to figure out how to post an Answerhub version of this problem/post.

In “Answers”, I explained this problem and received responses from the Staff on what could be causing it. I also explained how I was able to fix a project once it was corrupted. I wanted to close this topic and so, wanted to explain what caused it in my case (there are likely other project corruptions that have nothing to do with this, but what caused it for me, may offer insight if someone is doing something similar).

In my case, I had been using GEngine calls to display debug messages. On 4.6 and 4.7, any time I put a GEngine call in a constructor, or in a function being called from a constructor, it would work fine until I closed the project. On reopening, the project would be corrupted and the Editor would crash. While I don’t believe that crashing is an appropriate error handling method by the editor, it was creating some sort of error and not having the calls in there, keeps the problem from occurring.

In this instance, if you crash a project in this manner, it can be restored by manually editing your C++ code and removing the offending call (in my case GEngine), removing the Intermediate directory under “Unreal Projects/projname/”, then locating the dylib files in the Binaries directory of the project tree. When you restart, it will rebuild and the editor will be able to load.

My previous post mentioned TArrays, that had nothing to do with it and was a red herring due to TArrays having a bug in how they are handled in the Editor Play, I put the two bugs together thinking they were related, but they are not. It was GEngine.