What It Means & How to Fix It in UE5
🧠 Why You’re Seeing This Error
This error means that your Blueprint logic got stuck in a loop that ran too many times in a single frame, and Unreal shut it down to prevent the editor (or game) from freezing.
By default, UE5 allows a maximum of 1,000,000 loop iterations per frame. If your logic goes over that — even unintentionally — you’ll get this runtime error.
💥 Example Error Message
Blueprint Runtime Error: "Infinite Loop Detected" in [YourBlueprint]
🛠️ Common Blueprint Scenario
[While Loop]
Condition: (bIsReady == false)
Body: (Check condition again, never changes)
Or:
For Each Loop → Array with 1,000,000+ elements → Heavy logic inside
If the condition never becomes false or the array is huge, Unreal halts the loop.
✅ How to Fix It in UE5 – Step-by-Step
✔️ 1. Add a Valid Exit Condition
Make sure the loop actually ends:
While (bReady == false)
→ Check condition
→ If true, set bReady = true
If nothing updates the loop condition, it will run forever.
✔️ 2. Avoid Infinite Loops in Construction Scripts
Construction Scripts run in the editor, not just during gameplay. Avoid any looping logic there unless it’s very controlled.
✔️ 3. Limit How Much Work You Do Per Frame
For large data sets:
- Use ForEachLoopWithBreak
- Spread work across multiple frames using Timers or latent nodes
- Use Delay or Retriggerable Delays in loops that run over time
✔️ 4. Add a Watchdog Variable for Safety
Example:
[While Loop]
→ Add 1 to LoopCounter
→ If LoopCounter > 1000 → Break or return
This helps prevent infinite execution paths.
✅ Summary: How to Fix “Infinite Loop Detected” in UE5
| Cause | Fix Example |
|---|---|
| Loop condition never changes | Make sure something breaks or exits the loop |
| Huge array or processing load | Use ForEachLoopWithBreak, timers, or delays |
| Logic placed in Construction Script | Move looping logic to runtime events like BeginPlay |
| Uncontrolled recursion or callbacks | Add checks, limits, or delays to break the cycle |
