InvalidStateError: Failed to read the 'responseText' property from 'XMLHttpRequest'

[RealAlphabet]

There is a logic error in the default XHR loader code of HLS. response can be null if the request failed.

Also in accordance with the specification.

Note: When setting responseType to a particular value, the author should make sure that the server is actually sending a response compatible with that format. If the server returns data that is not compatible with the responseType that was set, the value of response will be null.

InvalidStateError: Failed to read the 'responseText' property from 'XMLHttpRequest': The value is only accessible if the object's 'responseType' is '' or 'text' (was 'arraybuffer').
    at t.readystatechange (https://cdnjs.cloudflare.com/ajax/libs/hls.js/1.4.0/hls.min.js:1:351569)

Here is the line corresponding to the error. https://github.com/video-dev/hls.js/blob/a58ce98ffe60085ad1ec8c21a918cc9a8016c419/src/utils/xhr-loader.ts#L202

[RealAlphabet]

After a long time debugging and reading the logs of the users for whom the error was triggered I noticed other errors such as :

RangeError: Array buffer allocation failed
    at new ArrayBuffer (<anonymous>)
    at new Uint8Array (<anonymous>)
    at _t (https://cdnjs.cloudflare.com/ajax/libs/hls.js/1.4.0/hls.min.js:1:25511)
    at e.bufferFragmentData (https://cdnjs.cloudflare.com/ajax/libs/hls.js/1.4.0/hls.min.js:1:122074)
    at e._handleTransmuxComplete (https://cdnjs.cloudflare.com/ajax/libs/hls.js/1.4.0/hls.min.js:1:215672)
    at e.handleTransmuxComplete (https://cdnjs.cloudflare.com/ajax/libs/hls.js/1.4.0/hls.min.js:1:196369)
    at e.onWorkerMessage (https://cdnjs.cloudflare.com/ajax/libs/hls.js/1.4.0/hls.min.js:1:195871)
    at Worker.onwmsg (https://cdnjs.cloudflare.com/ajax/libs/hls.js/1.4.0/hls.min.js:1:192471)

Then I found an interesting information in the specification, here it is. https://xhr.spec.whatwg.org/#the-response-attribute

5. If this’s response type is "arraybuffer", then set this’s response object to a new ArrayBuffer object representing this’s received bytes. If this throws an exception, then set this’s response object to failure and return null.

Allocating an ArrayBuffer object is not guaranteed to succeed. [ECMASCRIPT]

I think that both errors are closely related to the same problem, namely that the user does not have enough free memory on his device, or a memory allocation bug.

[robwalch]

Hi @RealAlphabet,

Is this something you can still reproduce? Have you tried catching the exception, and/or taken steps to reduce memory usage?