Multiple Components – Hydration errors in Next.js 15 (React 19)

[hemahg]

Describe the problem
After upgrading our project from Next.js 14 to Next.js 15 (which uses the latest React version), we are encountering hydration errors across multiple PatternFly components.

The issue appears consistently for most PatternFly components (e.g., Button, Dropdown, Modal, DatePicker, etc.), not just a single component.

To isolate the problem, I created a minimal fresh Next.js 15 application and installed PatternFly. The hydration error still occurs there, which suggests this may be related to compatibility between PatternFly and Next.js 15 / the latest React version.

How do you reproduce the problem?
1.Create a new Next.js 15 or Next.js16 app:
npx create-next-app@latest
2. Install PatternFly:
npm install @patternfly/react-core
3Import and render a simple PatternFly component (e.g., Button) inside a page..
4.Run the app in development mode.
5.Open the browser → hydration error appears in console.

Expected behavior
PatternFly components should render without hydration errors in a Next.js 15 application, just as they did in Next.js 14.

Is this issue blocking you?
Yes — this is currently blocking our upgrade to Next.js 15.

Screenshots

What is your environment?
OS: macOS (also reproducible on Linux)
Browser: Chrome
Next.js: 15.x

What is your product and what release date are you targeting?
We are upgrading our https://github.com/streamshub/console application to Next.js 15 and targeting an upcoming release is in march 18th .

Any other information?

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Jira Issue: PF-3620