Puppeteer: Unable to get extension from Realm

Extension lookup is attempted for a worker realm that does not support it.

Error message

Unable to get extension from Realm

How this error happens

An internal extension lookup was requested from a worker realm that does not support that lookup. A worker is not a page’s extension execution world.

The failing snippet assumes page already owns a dedicated worker. The fix uses its extension-enabled browser.

const worker = page.workers()[0];

const handle = await worker.evaluateHandle(() => {
    return globalThis;
});

How to fix

Look up extensions through the browser’s extension API rather than trying to derive extension ownership from a worker handle.

const extensions = await browser.extensions();

for (const [id, extension] of extensions) {
    console.log(
        id,
        extension.name
    );
}

Things to keep in mind

The worker evaluation itself is valid and does not guarantee this error. It identifies the realm involved; the error appears only if an extension-aware integration subsequently asks that worker realm for an unsupported extension lookup. Dispose the handle after use.

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