# Black box on calling stopRenderVideo

**URL:** <https://devforum.zoom.us/t/black-box-on-calling-stoprendervideo/52629>\
**Category:** Web\
**Created:** [June 17, 2021, 7:36am UTC](https://devforum.zoom.us/t/black-box-on-calling-stoprendervideo/52629 "2021-06-17T07:36:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![sri.soham](https://avatars.discourse-cdn.com/v4/letter/s/5f9b8f/32.png) [@sri.soham](https://devforum.zoom.us/u/sri.soham)\
**Post date:** [June 17, 2021, 7:36am UTC](https://devforum.zoom.us/t/black-box-on-calling-stoprendervideo/52629/1 "2021-06-17T07:36:14Z")

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**Description**  
Whenever stopRenderVideo is called, video stops and a black box appears in its place.  
I am rendering multiple videos on the same canvas. When a user leaves the meeting, stopRenderVideo(canvas, user\_id) is called for that user and we are seeing black box instead of transparency in place of the video.

stream.clearVideoCanvas did not help.  
When I tried to get the context of the canvas to clear the rectangle, I got an error saying, “Cannot get context from a canvas that has transferred its control to offscreen”.

So, how do I get rid of that black box.

**Which Web Video SDK version?**  
1.0.3

**To Reproduce(If applicable)**  
Call stopRenderVideo and you should be able to see it.

**Screenshots**  
 ![zoom_vpix_black_box](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/2/d/2d2a8b3422578b61714a94c33cb370809edf137d.png)

This is happening on firefox and chrome on ubuntu and mac.

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**Author:** ![vic.yang](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/vic.yang/32/24656_2.png) [@vic.yang](https://devforum.zoom.us/u/vic.yang)\
**Post date:** [June 17, 2021, 8:18am UTC](https://devforum.zoom.us/t/black-box-on-calling-stoprendervideo/52629/2 "2021-06-17T08:18:18Z")

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Hey @sri.soham

Thanks for your feedback. We have found the problem and it will be fixed in the next release. Currently, you can try to hide the canvas element when all videos stopped as a workaround.

Thanks  
Vic

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**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/6/1/614bdd549b610bbaa46ff934617683a02bdaa03c.png) [@system](https://devforum.zoom.us/u/system)\
**Post date:** [July 17, 2021, 6:19pm UTC](https://devforum.zoom.us/t/black-box-on-calling-stoprendervideo/52629/3 "2021-07-17T18:19:09Z")

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Closed on July 17, 2021, 6:19pm UTC

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