NullPointerException in WebpFrameLoader#onFrameReady

[superxlcr]

crash stacktrace:
java.lang.NullPointerException: Attempt to invoke interface method 'void com.bumptech.glide.integration.webp.decoder.WebpFrameLoader$a.onFrameReady()' on a null object reference
at com.bumptech.glide.integration.webp.decoder.WebpFrameLoader.onFrameReady(WebpFrameLoader.java)
at com.bumptech.glide.integration.webp.decoder.WebpFrameLoader$b.handleMessage(WebpFrameLoader.java)
at android.os.Handler.dispatchMessage(Handler.java)
...

library version: 2.0.4.11.0

related code:
// The callbacks may unregister when onFrameReady is called, so iterate in reverse to avoid
// concurrent modifications.
for (int i = callbacks.size() - 1; i >= 0; i--) {
FrameCallback cb = callbacks.get(i);
cb.onFrameReady();
}

it seems like the FrameCallback got from callbacks list is null

[zjupure]

You subscribe a null callback to WebpFrameLoader?