Playground Error on most recent version

Pryme8 · March 25, 2026, 9:39pm

I keep getting this error when I run playgrounds on the newest version. But when I downgrade to 7.** it does not drop.

Pryme8 · March 25, 2026, 10:04pm

Also arrow keys are not working on control attach?

Joe_Kerr · March 26, 2026, 7:50am

The newest version is always just https://playground.babylonjs.com, right? If so, I tried Firefox and Chrome. All good

Evgeni_Popov · March 26, 2026, 9:10am

Would you have a repro we can use to test on our side?

I tested a number of PGs and didn’t get this error.

Pryme8 · March 26, 2026, 3:57pm

The funny part is now that 9.0 is on the PG I cant get it to drop anymore as well… o_O.

Must have just been some oddity with my local client and the last version we had up.

Evgeni_Popov · March 26, 2026, 7:59pm

Actually, I had the error twice when testing PGs before deploying v9!

We’ll try to fix this issue, but since it happens so rarely, it’s a bit more complicated…

[EDIT] This PR should fix it:

github.com/BabylonJS/Babylon.js

fix(buildTools): fix regex that replaces external type references with 'any' in declaration generation (#18184)

master ← Popov72:fix-monaco-ts

opened 08:23PM - 26 Mar 26 UTC

Popov72

+6 -4

## Problem The playground intermittently shows: > Error at [193832, 2]: /exter…nal/babylon.global.d.ts:193832:2 ',' expected. This is caused by the declaration generator (`generateDeclaration.ts`) producing **syntactically invalid `.d.ts` output** when replacing `@fluentui`/`@fortawesome`/`@recast-navigation` type references with `any`. The regex has two bugs: 1. **Greedy trailing pattern eats colons** — `[^,;\n>) ]*` after the alias consumes `:`, turning `export var ThemeModeSD: SD<ThemeMode>` into `export var any SD<any>` (colon swallowed, producing a parse error). 2. **Matches declaration names** — The regex replaces the alias even when it appears as the *declared name* (after `type`, `class`, `var`, etc.), producing invalid syntax like `export type any = ...` or `export class any implements ...`. Currently, `babylon.inspector-v2.d.ts` on `preview.babylonjs.com` has **5 broken declarations** from this bug (lines 135, 139, 144, 161, 187). ## Fix Use exact alias matching (the same pattern already used for `react` replacements) plus a negative lookbehind to skip declaration sites. Both locations in `generateDeclaration.ts` (module declarations and namespace declarations) are fixed. | Test case | Old regex | Fixed regex | |---|---|---| | `export type ThemeMode = ...` | :x: `export type any = ...` | :white_check_mark: Kept as-is | | `var ThemeModeSD: SD<ThemeMode>` | :x: `var any SD<any>` | :white_check_mark: `var ThemeModeSD: SD<any>` | | `export class ThemeResolver ...` | :x: `export class any ...` | :white_check_mark: Kept as-is | | `export var ThemeServiceId: ...` | :x: `var any unique symbol` | :white_check_mark: Kept as-is | | Type references (params, generics, unions) | :white_check_mark: Replaced with `any` | :white_check_mark: Replaced with `any` |

Pryme8 · March 26, 2026, 8:41pm

Ok cool, so I was not crazy . Thank you.

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Playground Error on most recent version

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