> This page is for SDK, version Legacy.
> For other versions, use one of these documentation indexes:
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> - Legacy: https://buildwithfern.com/learn/sdks/legacy/llms.txt

> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. For task-scoped instructions for coding agents working in a Fern project, see https://buildwithfern.com/learn/home/fern-instructions.md.

## 2.30.11

**`(fix):`** Optional parameters whose type is a union containing `mixed` are now type-hinted as `mixed` instead of `mixed|null`. PHP rejects `mixed|null` with a fatal error ("Type mixed can only be used as a standalone type"), so the generated client failed to load.