Open Level broken on HTML5 Shipping builds

In UE 4.10.0, I am able to successfully use the Open Level BP node in an HTML5 Development build. However, when I build for HTML5 in Shipping mode, the browser crashes after loading (when the game starts playing).

Steps to reproduce:

  1. Create a new project from the Blueprint First Person template.

  2. Create a duplicate map by selecting File ==> Save As: Map2. (Feel free to change some of the material colors, etc. before saving your copy, it will make it easier to tell when you’ve successfully changed levels.)

  3. Open up the Level Blueprint. Set up 2 input keys that trigger Open Level nodes when Pressed. One Open Level node should have Level Name: FirstPersonExampleMap, the other Open Level node should have Level Name: Map2. Make sure to copy these nodes to the Level Blueprints for both of your maps!

  4. Make sure all your maps are set to be packaged: Edit ==> Project Settings ==> Packaging ==> (expand Packaging section using drop-down arrow) ==> List of maps to include in a packaged build: add FirstPersonExampleMap and Map2.

  5. In the Project Settings ==> Packaging menu, set Build Configuration: Development.

  6. File ==> Package Project ==> HTML5. Select output location,. Once packaging has finished, go to the output location, run HTML5LaunchHelper, go to localhost:8000, and click on projectname.html. You should be able to use the hotkeys you set in the Level Blueprint to swap between maps. (Or, you can use ~ to bring up the console, then type Travel mapname.

  7. Now, back in Project Settings ==> Packaging, change the Build Configuration to Shipping. Feel free to enable Full Rebuild, it doesn’t seem to matter either way.

  8. Finally: File ==> Package Project ==> HTML5. Select output location, run HTML5LaunchHelper, go to localhost:8000, click on projectname-HTML5-Shipping.html. Once the project has loaded, the browser hangs and crashes.

Let me know if any further information or reproduction steps are required.

Please note that this is NOT the same bug outlined here: Open Level doesn't work in standalone game - Blueprint - Epic Developer Community Forums

The linked question deals with the Open Level node when launching a standalone game from within the editor. I am having issues with the Open Level node specifically when packaging Shipping builds for HTML5.

Hello ,

I tested this on our end and was able to travel between levels in packaged shipping build. I have a few questions for you that will help narrow down what issue it is that you are experiencing.

Quick questions:

  1. Were you able to reproduce this issue in a clean project?
  2. If so, could you provide any steps that may have been left out of your original post?
  3. If not could you provide the project that you are having issue with?

Upon another test this morning, everything seems to be working fine. I was getting frequent crashes when running WebGL projects in Firefox Nightly last week. In this case I misinterpreted them as UE4-related :slight_smile:

I am happy to hear that you have things working on your end. I am going to accept your last comment as an answer. If this issue occurs again please feel free to reopen this thread with additional information.

Make it a great day