So you’re working on a game or a project in Unreal Engine 5 (UE5), everything looks great, you hit “Package”, and then… oh no! You get hit with the dreaded:
PackagingResults: Error: Unknown error
It’s vague. It’s maddening. But don’t worry! This guide will help you make sense of it—and fix it! Let’s figure this out together, like a couple of debugging detectives 🕵️♀️🕵️♂️
Contents
TLDR: Too Long, Didn’t Read
If you’re getting “Error: Unknown error” in UE5 during packaging, start by checking the Output Log for more details. Common issues include missing files, weird characters in project paths, outdated plugins, or memory limits. Use clean packaging methods, update your engine, and check your code. Read on for a step-by-step way to fix it!
1. Start with the Output Log
When UE5 just says “Unknown error”, that’s not the whole story. The real clues are hiding in the Output Log.
Here’s what to do:
- Go to Window → Developer Tools → Output Log
- Scroll to the bottom of the log
- Look for errors in red text
These will usually give you better details, like “Could not compile X module” or “Missing shader X”. Don’t worry if it looks scary—we’re going to walk through some of the most common causes.
2. Check Your File Paths
UE5 can get very fussy about where your files are stored. If any folder in your project path has special characters, or even if your path is too long, it can break the packaging process.
Fix it by doing this:
- Move your project to something simple like C:\UE5Projects\MyGame
- Make sure your folder names do not include spaces, symbols, or non-English letters
This one fix alone solves it for a lot of people!
3. Clean and Rebuild
You might just have a bad build cache or metadata that’s causing problems.
Try a clean build:
- Close the Unreal Editor
- Navigate to your project folder
- Delete these folders:
- DerivedDataCache
- Intermediate
- Saved
- Open your project again
- Try packaging
It will take longer to load the first time again since UE5 will rebuild the cache—but it’s worth it!
4. Update Everything
Unreal Engine is always improving. So if you’re using an older version, some bugs might already be fixed in a newer release.
- Update to the latest stable version of UE5
- Update your plugins—old plugins cause big headaches
- Update your graphics drivers (especially for NVIDIA users)
Sometimes fixes just come down to having up-to-date tools.
5. Watch Out for Plugins
Custom or third-party plugins can throw the whole packaging process into chaos. If one of them isn’t compatible with your project or UE5 version, it’ll silently ruin everything.
Isolate the culprit:
- Disable all optional plugins
- Try building again
- Turn them back on one-by-one to find the guilty one
Don’t forget to check the Log—it may name-drop the plugin causing trouble.
6. Make Sure You’re Packaging For the Right Platform
If you’re accidentally trying to build for a platform you don’t have fully configured (like Android or iOS), weird errors can happen.
Here’s what to double-check:
- Go to Platforms in Project Settings
- Pick the one you really want: Windows, Mac, etc.
- Make sure the proper SDK is installed
This may sound simple, but we’ve all done it—trying to build for Android when we meant Windows!
7. Is Your Hard Drive Full?
Yes, it’s silly. But if your disk is almost out of space, the engine might crash without a helpful message. It’s embarrassing… but real.
How to check:
- Go to File Explorer
- Right-click your drive → Properties
- Check your free space
Make sure you have at least a few gigabytes of space for compiling and temporary files.
8. Use Development Configuration First
Trying to package in “Shipping” mode before testing in “Development” can be a fast track to pain.
Always build in Development first.
Why? Because it gives better debugging messages and doesn’t assume your project is final-perfect-polished-ready.
Switch your packaging configuration in the top right before building:
- File → Package Project → Build Configuration → Development
Once that works, then try Shipping mode.
9. Check Your Blueprints and Code
If even one Blueprint node is broken, or one line of code is buggy, the whole packaging will stop.
Scan your Blueprints:
- Open every Blueprint one at a time
- Watch for any Compile Error messages at the top
Check your C++ code too if you’re using it. Just one missing semicolon can ruin your day.
10. When In Doubt, Google the Exact Log Message
Remember that Output Log from earlier? Copy the full error message and Google it (or ChatGPT it!).
You’re not in this alone. Someone has definitely hit that problem before.
Stack Overflow, Unreal forums, Reddit—they’re all full of people who fixed the same issue you’re facing now.
Bonus Tips for Maximum Safety
- Use source control (like Git) so you can rollback broken builds
- Make backups before trying drastic fixes
- Turn on Full Verbose Logging if you’re really stuck
- Try creating a blank new project and package it to test if the issue is your system or your project
Final Thoughts
“Unknown Error” doesn’t mean “Unfixable Error.” It just means you’ve got some detective work to do. Hopefully, this guide made your search a little easier—and more fun!
Stay patient, take it step by step, and remember: every great developer once stared at that same error and thought, “Huh?!”
You’ve got this 🎮🔥
