Fresh project package fail, UE 5.0

General Issues and Bug Reporting
,
1

Hey all,
I am getting the following error when attempting to package my new project: System.IO.FileNotFoundException:
Could not load file or assembly ‘System.Runtime, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’. The system cannot find the file specified.

File name: ‘System.Runtime, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’

I have a feeling that it’s an easy fix that I just keep glossing over, but I haven’t yet been able to find a fix, or what files/SDKs I’m missing. This is a new UE 5.0 C++ project built from an unaltered source build on VS 2022. If anyone knows a fix for this, or a helpful link, it would be much appreciated.

2

that’s weird. maybe you need to install .net.
i’d recommend you to install it through visual studio installer, if that’s what you installed.

https://dev.epicgames.com/documentation/en-us/unreal-engine/setting-up-visual-studio-development-environment-for-cplusplus-projects-in-unreal-engine?application_version=5.0
for 5.0 it does not specify which version. but if you follow the instructions on the web you’ll be fine.

5.5 requires .net 8.0 according to the site.
check the version of that page that corresponds with your engine version.

i’d avoid installing .net manually (outside of visual studio installer) if you have vsinstaller already.

3

I double checked, just to be safe, and I currently have .NET 6, 7, 8, and 9 installed through VS. Unless something installed wrong, I should be OK on that side of things.

4

i’m sorry i don’t know what else could it be.
would you be able to share the logs ?

6

JustWar5_2.log (909.8 KB)

7

So I was able to package the project in VS, but cooking in editor still yields the same error message. So it looks like all the necessary items are on m PC, and the editor is just having trouble accessing them.

8

thanks.
you have a ton of these lines.

[2025.05.26-14.33.41:222][ 0]LogAssetRegistry: Error: Package E:/JustWar2/EngineV2/UnrealEngine/Engine/Content/EngineMaterials/Substrate/Glints2/dict_0007_0185.uasset is too new. Engine Version: 1004 Package Version: 1009

the logs says you’re using 5.0, but those assets are meant for a newer version apparently.
try to load it with 5.1 or 5.2 or a later one.