Found in

• 111.0b4 flatpak (20230221190142)

Affected versions

• 111.0b1 (20230214145154) Beta
• 112.0a1 (20230220165121) Nightly

Tested platforms

• Affected platforms: Ubuntu 20.04, Win10.
• Unaffected platforms: will update

Steps to reproduce

1. Open the following link (https://www.crazygames.com/t/webgl).
2. From the game list select Smash Karts.
3. Click on this game.
4. Select play now.
5. Wait while it loads.
6. After it loads press play.

Expected result

• I get this error: "An error occurred running the Unity content on this page. See your browser JavaScript console for more info. The error was:
  RuntimeError: indirect call to null
  @https://smashkartsgc.b-cdn.net/Build2020New/43eacaa5c53e5b7b614034d6c2064aae.wasm.br:wasm-function[35419]:0xc5cecd". (For more details see screenshot attached)

Actual result

• No error should be displayed.

Regression range

• Will look for one.

Additional notes

• Issue does not reproduce on Chrome.
• I do not have a user for this site.

I couldn't find an exact patch, but mozregression shows first bad build is: build_date: 2019-06-04
pushlog_url: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=6d71d3ca012438d7eac6e8f9471e198a10eabc70&

Correct link: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=6d71d3ca012438d7eac6e8f9471e198a10eabc70&tochange=21d22b2f541258d3d1cf96c7ba5ad73e96e616b5

Regression window from local cached build:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=986dc438181cafa24b2decc06193164029a5b342&tochange=76f821a99146f3d472886701d0782cc4506c2507

Setting dom.promise_rejection_events.enabled to false in the above bad build fixes the error.
So, The patch of bug 1525554 causes the issue.

(unfortunately, the preference has already been removed by Bug 1578241 )

Set release status flags based on info from the regressing bug 1525554

:edgar, since you are the author of the regressor, bug 1525554, could you take a look?

For more information, please visit auto_nag documentation.

The error seems from https://searchfox.org/mozilla-central/rev/3ede9deb876ad5d6389cb51b371d4a4c8d788deb/js/src/wasm/WasmBuiltins.cpp#715, so switch to JavaScript: Webassembly.

In the Chrome's DevTools you can see the same exception, in console logs. But it was not surfaced by UI to the popup. Looks like wasm in the Firefox behave the same way as in Chrome. Does bug 1525554 affect how wasm exceptions are reported to the frontend?

After bug 1525554, if there is a unhandled rejected promise, there will be a PromiseRejectionEvent fired, I assume page doesn't handle the rejected promise caused by wasm exception, but not sure why there is no popup in Chrome.

Set release status flags based on info from the regressing bug 1525554

Moving this back to DOM Core & HTML based on the regressing bug. This error was pre-existing and happens in both browsers, but it's only being presented to the user because of the promise rejection error.

I can no longer reproduce this with Nightly Fx 129, or with the old Fx 111, on Win 11. I suspect the side fixed this problem on their end.

Hi Monica Chiorean, can you please verify if this is resolved to you, too? Thank you.

Could not reproduce it with RC 127.0.1 and Nightly 129.0a1 on neither Win10/Ubuntu 23.10.

Thanks for the verification.