WebGL: CONTEXT_LOST_WEBGL: loseContext: context lost

Hi forum, in Safari we had sometimes the following error in JS console: WebGL: CONTEXT_LOST_WEBGL: loseContext: context lost (s. screenshot):

Any ideas how to solve that problem?

Do you still see the model in the viewer? Does anything unexpected happen except the console error?

It would be great if you could give me more information about the problem with a model link and a minimal version of the definition causing this so we can reproduce it.

There are two viewports. One of them is empty after the error. The other one still shows the object. Unfortunately, every interaction with JS is no more possible because of the error.

What we do: By clicking on a icon the second viewport is shown as an overlay over the whole website, full width and full height. Then, by clicking on another icon the overlay gets back to its normal size (s. attachment). And then the first viewport is empty and the error is thrown (only in Safari, and not always!).
viewports|690x493 (249.1 KB)

I didn’t manage to reproduce the issue with the model you shared and without more details it’s hard to troubleshoot this. Could you share a link to your project so we can investigate further?

Also, do you get the same error in Chrome?

I’m sorry for replying late. I had first to prepare a prototype because the original model is confidential.
Please check Locherschmuck Shop und Konfigurator: Konfigurieren, and click on the focus view (s. attachment). Sometimes in Safari after opening and closing the big view, JS is hanging and no action is possible anymore. I know that sometimes also in FF or Chrome there are little flaws but actions are still possible…

Thank you very much for sharing this. Our development team will investigate further and I get back to you once we know more.

Hi Pavol, do you have any news for us? Thanks for your answer.

Hi Guys,

I’ve had a new user report ‘WebGL context was lost error’ on a KaroroCAD.online session twice now.

Is there any insight as to why he would have seen this?



This is an issue related to the use of WebGL in a browser, and most likely is not directly related to ShapeDiver. Usual causes are running old GPUs or launching multiple tasks involving the GPU simultaneously, which could cause too much strain. Connectivity issues might be responsible too. The user could try to make sure all other applications on his computer are closed, try different web browsers, or make sure he is using a good wifi connection.

If this issue gets reported by multiple users on your end, then it might be caused by something that the ShapeDiver viewer does in particular, but so far we have not gotten reports from other users indicating such an issue.

Hi Mathieu,

Thank you for your fast reply - that makes sense.