How to figure out what is causing Fatal Error on packaged build?

So I’ve completed my first project in UE5 and come to package it. It’s run through everything and said it’s all complete. I go to run the .exe file to check and it’s all fine…on my machine.

I asked someone else to run the .exe on their machine (with identical specs) and when it boots it gives a Fatal Error message.

How can I find out what’s causing this?

Did you ever solve this? I’m having the same issue. It works fine on my machine but throws fatal error on any other computer?

I did!

however to be honest I completely forgot I posted this question and I’ve also had to make further changes since solving this one and I can’t remember what the original solution was.

I’ll have a think and post back if I do remember, sorry.

It’s quite possibly not the answer, and even more so not the solution for you; but I think one of the earliest fixes I did involved the Game Icon file. I think originally I just renamed a .jpg image to .ico hoping that would work. It showed fine in the Project Settings window, but it wasn’t until I actually made the file a proper .ico file that the project ran.
Like I said this may not be your solution, and I can’t remember if I did this fix before or after asking someone else to run it on their machine, but it definitely was an early fix for the issues I was having.

This article was really helpful for me: Debugging a Packaged Build | Unreal Engine Community Wiki

Greetings @brandav

That is indeed a great article! For anyone who comes across errors such as this I always recommend going in and pulling your crash log from your AppData folder. The popup in UE may not show the specific error all the time. But, the crash log will and will greatly help in identifying the root of the problem. I hope that’s helpful!