Cannot build project (UBT ERROR)

anonymous_user_dffed3981 · March 31, 2016, 3:11pm

Hello!
I cannot build my project due to some Unreal Build Tool error.
I’ve tried building for both Windows and Android but I get the same UBT error:

UnrealBuildTool: ERROR: UBT ERROR: Failed to produce item: 'filepath'.exe

I have attached the log file if you would like to take a look at it yourself.

I’m pretty new to Unreal. I’ve tried restarting Unreal and even my machine.

Sean_L · March 31, 2016, 7:04pm

Hello,

Are you able to package a clean, blank project successfully?
Does this occur if you try upgrading the project to 4.11 and packaging it there?
Have you tried deleting your saved and intermediate folders from your project and packaging again?

anonymous_user_dffed3981 · March 31, 2016, 10:22pm

I can build an empty project (or any other project) without problems. I do not currently have any other engine versions installed. Deleting the saved and intermediate folders didn’t help either.

Sean_L · April 3, 2016, 3:49pm

Are you working with a blueprint or code project?

anonymous_user_dffed3981 · April 3, 2016, 3:59pm

I have one C++ class as a parent for a couple of blueprints. However, I’ve been thinking about remaking the class as a blueprint and reparent the child classes. Do you think that would help?

Sean_L · April 3, 2016, 4:08pm

It’s worth a shot. It seems like some of the errors that you were getting may have been related to declaring a function in the header file, but not having any implementation of that function in the .cpp. Is that something that you have occurring in your project currently?

anonymous_user_fbe5155f · April 4, 2016, 12:22pm

Some things to try

Fix the redirectors (right click contents → Fix redirections)
There is a warning about a Class none, that may be related to the redirections.
Disable most plug-ins
Sometimes it’s been reported that Blueprints can fail compiling if they have underscore in their files (I have not had that issue personally)
Delete Binaries/Saved/Intermediate. Relaunch
Try Cook.

hope this helps.

Mauricio_N.Santos · September 5, 2016, 5:46am

Hi. I found a simple solution: execute Epic Laucher as administrator. After deleting Saved, Intermediate and Build folders, moved the project folder to other drive, because long path strings can be a problem for Unreal, I figured out that some administrative issues in Windows can bother.
All the best!

Edregol · June 1, 2017, 7:55pm

I upgrade my project from 4.15 to 4.16. Deleting the folders Binaries/Saved/Intermediate did the trick for me.
I still had to rebuild the project files(right click on the *.uproject file in your project folder) and I needed to upgrade the *.cs build files to 4.16 standards though.
Thanks for the advice!

vinstriano · May 27, 2018, 6:53pm

Thank you Keyleeeeee!!!

j_a_b · December 21, 2020, 7:36pm

In my case, probably after some deleting/renaming of classes, there were two CPP files for the conflicting class. One was in the Private folder as it should be but the other was in the Public folder. This plus 's steps solved my problem.