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PNaCl modules can only be used on the open webkeyboard_arrow_down

PNaCl modules can only be used on the open web

WebViewer provides PNaCl, WebAssembly and asm.js modules to allow for client side rendering of documents in many different browsers. Chrome is the only browser that supports PNaCl and as of Chrome 76 they have deprecated support for PNaCl modules unless you have enabled an origin trial on your website, though note that will only be valid until March 10, 2020 when PNaCl will be fully removed.

Below is the error message you might see in the browser console in Chrome 76:

PNaCl disabled

In this case WebViewer will automatically use the WebAssembly module so there won't be any problems loading documents. You have three options for how to handle this: ignore the error, hide the error or enable the PNaCl origin trial.

linkIgnore the error

As mentioned, WebViewer will automatically use WebAssembly so documents will continue to load without issues. You can safely ignore this error.

linkHide the error

If you just want to remove the error but don't care about enabling the PNaCl origin trial you can pass the constructor option backendType: 'ems' to WebViewer. This will force WebViewer to choose the WebAssembly or asm.js module and the error won't appear.

linkEnable origin trial

Although general WebAssembly performance in browsers is improving, the performance of PNaCl can still be better in some situations and you may want to continue using PNaCl until Chrome 80.

To do this you can register for the Chrome origin trial which will give you a token you can add to your page or response header to allow PNaCl to keep functioning. Register here.

To enable the origin trial on your website follow these steps.

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