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PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-05, 01:50
by truongtfg
Hello,

Recently when I tried to play videos from the courses purchased on Udemy, the videos could only play for 1 sec and then the screen went blank with the following error in the console:

Code: Select all

TypeError: 'block' member of ScrollIntoViewOptions 'center' is not a valid value for enumeration ScrollLogicalPosition.
Stack trace:
value@https://www.udemy.com/staticx/udemy/js/webpack/course-taking-v4-app.6cb3207d02b984a68d57.js:45:523898
G/s<@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:68527
Fi@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:90141
Li@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:85691
Pi@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:85043
Ni@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:91118
fe@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:75762
pe@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:101038
ae@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:96488
M@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:85884
n@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:85315
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
y/a.dispatcher@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
e@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:322169
./node_modules/video.js/es5/component.js/p</u.prototype.trigger@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:111285
@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:230234
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
y/a.dispatcher@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
e@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:165:15519
  
entry-vendor.9872dd3fd04654d9af0c.js:165:10826
	wrapMethod/e[o] https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:165:10826
	gs https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:67885
	Os/n.callback https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:72615
	fr https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:45774
	cr https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:45526
	Fi https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:90407
	Li https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:85691
	Pi https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:85043
	Ni https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:91118
	fe https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:75762
	pe https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:101038
	ae https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:96488
	M https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:85884
	n https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:85315
	r https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
	y/a.dispatcher https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
	e https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:322169
	./node_modules/video.js/es5/component.js/p</u.prototype.trigger https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:111285
	<anonymous> https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:230234
	r https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
	r https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
	y/a.dispatcher https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
	e https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:165:15519
VIDEOJS: ERROR: TypeError: 'block' member of ScrollIntoViewOptions 'center' is not a valid value for enumeration ScrollLogicalPosition.
Stack trace:
value@https://www.udemy.com/staticx/udemy/js/webpack/course-taking-v4-app.6cb3207d02b984a68d57.js:45:523898
G/s<@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:68527
Fi@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:90141
Li@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:85691
Pi@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:85043
Ni@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:173:91118
fe@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:75762
pe@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:101038
ae@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:96488
M@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:85884
n@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:145:85315
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
y/a.dispatcher@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
e@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:322169
./node_modules/video.js/es5/component.js/p</u.prototype.trigger@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:111285
@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:230234
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
y/a.dispatcher@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
e@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:165:15519
  
entry-vendor.9872dd3fd04654d9af0c.js:165:10826
VIDEOJS: ERROR: TypeError: this.el_ is null
Stack trace:
./node_modules/video.js/es5/tech/html5.js/</c.prototype[e]@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:262836
get@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:303798
f/d<@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:303152
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
y/a.dispatcher@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
e@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:165:15519
  
entry-vendor.9872dd3fd04654d9af0c.js:165:10826
VIDEOJS: ERROR: TypeError: this.el_ is null
Stack trace:
./node_modules/video.js/es5/tech/html5.js/</c.prototype[e]@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:262836
get@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:303798
f/d<@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:303152
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
r@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:326182
y/a.dispatcher@https://www.udemy.com/staticx/udemy/js/webpack/videojs-open-source-package.96c880a480c696aad5e5.js:1:325383
e@https://www.udemy.com/staticx/udemy/js/webpack/entry-vendor.9872dd3fd04654d9af0c.js:165:15519
  
entry-vendor.9872dd3fd04654d9af0c.js:165:10826
XML Parsing Error: no root element found
Location: https://www.udemy.com/api-2.0/users/me/subscribed-courses/1430746/lectures/8639766/progress-logs
Line Number 1, Column 1:
I have tried Palemoon 28.2.2 on Mx Linux and Linux Mint XFCE 64 bit and the same problem persisted.

When I use Firefox the videos play perfectly.

Thank you

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-06, 15:31
by therube
Is there some publicly available URL to one of these videos?

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-06, 20:40
by coffeebreak
therube wrote:publicly available URL to one of these videos?
Udemy's front page displays some courses. The pages of the courses list publically accessible "preview" videos along with the others, a ways down the page under the heading Course content (an example).

Most(?) of the preview videos apparently don't provide url links, though here is one that does.

I'm not on Linux and don't know if the preview videos are comparable, but I can say I had no problem playing them using PM 28.2.2 (Win 7 x86).

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-07, 14:16
by truongtfg
Publicly preview videos can be played just fine, the problem lies with the other videos. Here is a little screencast showing how it looks like when I continues the course.
Image

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-07, 19:08
by coffeebreak
truongtfg wrote:Publicly preview videos can be played just fine, the problem lies with the other videos. Here is a little screencast showing how it looks like when I continues the course.

Thank you for the screenshot, but as requested above, troubleshooting requires access to a problem video, to try to play it.

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-07, 19:13
by yami_
But this is a video, not a screenshot.

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-07, 21:27
by Moonchild
yami_ wrote:But this is a video, not a screenshot.
It's a (rather low framerate) screencast - it doesn't help because the screencast "plays" fine -- being able to see the actual problem in action (not just visually, but in underlying code too) with a problematic video will allow further investigation. The console errors are likely related (the bottom ones anyway) and it's just as likely this is a framework issue since that's what they seem to be using -- and it's throwing errors on the es5 shim which makes no sense since we have full es5 and es6 support, anyway (unless you're using PM 27.* or older)

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-07, 22:07
by coffeebreak
yami_ wrote:But this is a video, not a screenshot.
Off-topic:
I see now. It was needed to allow something additional in the adblocker to see it as a screencast. Thanks for pointing it out.

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-08, 02:27
by truongtfg
I have created an Udemy account with a registered course in it for you guys to test:
Moderator note: credentials removed.

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-08, 08:37
by Moonchild
Please don't post login credentials in public posts (unless you operate the server yourself and are aware of the potential abuse you open yourself up to).

The problem seems to be that the React framework is tripping over an arbitrary draft spec change.
The spec change can be addressed by porting something Mozilla added to Firefox 58. Hopefully that will solve the video issue. See bug #1389274.

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-08, 09:22
by truongtfg
@Moonchild: thank you for your remark :thumbup: , I was too naive. The account I posted was newly created and it uses a disposable email, and I thought that it would be okay. Anyway, next time I will send private message instead. Hope that the issued is solved in the next version of Palemoon, so that I can ditch Firefox :D

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-08, 09:29
by Moonchild
I'll give this some priority, but it may not make it into 28.3 without help. If someone wants to tackle the code porting of Issue #927 (UXP) (looks relatively straightforward at first glance) in the next day or at most 2, then I can uplift it. Otherwise it'll have to wait until 28.4.

UPDATE: I'm looking into this today to see if I can make a quick fix for it.

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-11, 02:34
by truongtfg
This is great Moonchild, thank you and all the devs for putting so much effort in developing Palemoon. Now I will send you guys some cups of coffee :D

Re: PM 28.2.2 can't play videos on Udemy

Posted: 2019-01-11, 10:37
by Moonchild
Pale Moon 28.3.0 should be able to play these videos once it's released.