# MobX 6.15.1

- Product: MobX (https://whatsnew.fyi/product/mobx)
- Vendor: MobX
- Date: 2026-05-04
- Version: 6.15.1
- Original notes: https://github.com/mobxjs/mobx/releases/tag/mobx%406.15.1
- Permalink: https://whatsnew.fyi/product/mobx/releases/6.15.1

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **fixed** — Make FlowCancellationError a proper Error instance while preserving its previous string representation
- **added** — Export CancellablePromise from the public mobx entrypoint

###### Patch Changes

-   [`df81c144fb148b64140d761aa61f032a7f429e12`](https://github.com/mobxjs/mobx/commit/df81c144fb148b64140d761aa61f032a7f429e12) [#4523](https://github.com/mobxjs/mobx/pull/4523) Thanks [@exzos28](https://github.com/exzos28)! - Make `FlowCancellationError` a proper `Error` instance while preserving its previous string representation.

-   [`21fc4de6c09a77caf115aedd2fe6df972637412b`](https://github.com/mobxjs/mobx/commit/21fc4de6c09a77caf115aedd2fe6df972637412b) [#4626](https://github.com/mobxjs/mobx/pull/4626) Thanks [@kubk](https://github.com/kubk)! - Export `CancellablePromise` from the public `mobx` entrypoint.