Crash on start when running packaged game with UsePakFile on

We get crash on start when starting packaged game.
In debug cook log :

Assertion failed: Offset >= 0 [File:f:\Unreal\Code415\UnrealEngine-4.15\Engine\Source\Runtime\PakFile\Private\IPlatformFilePak.cpp]

We are trying to upgrade our project from 4.12.5 to 4.15
Everything works apart from this important issue

Any suggestions?



I have been able to package and successfully run a game using Use Pak File from the Project Settings. Are you able to replicate this issue in a newly created project? If not, please delete your Intermediate and Saved folders and test it out again.

Thank you!

It works with new project.
But with our upgrading project it fails even if I have deleted intermediate and save folders from our project (and also DerivedDataCache, and …\AppData\Local\UnrealEngine\4.15) :frowning:

How to check what fails?
Any suggestions?


Since you upgraded from 4.12.5 to 4.15, it may be wise to create a copy of your project, then migrate the files over to a newly created 4.15 project and reset the project settings. That should ensure the files are clean for packaging.

Please include the full error output log if you run into another error, or even the same project logs may be useful too.