Prismic Toolbar/ Preview causing exceptions in IE 11

On Friday , our prismic website starts giving exceptions on IE 11. We have not done any modifications in the code at the time. When we removed the code for prismic toolbar/preview, the website started working again on IE 11.

While I understand IE 11 browser is no longer officially supported but this is strange that it started causing problem suddenly on Friday while it was working fine earlier.

Can you pls look at the issue and suggest a solution?

Hi Kapil,

We've recently made some updates to the toolbar to make it more lightweight and therefore more performant. It sounds like from the timing that this is where the issue arose for IE 11.

I'm investigating this further with the dev team and I'll get back to you once I know more.


Just one follow up question. Is this breaking your website for users not logged in to Prismic?

Hi Phil,

yes, the breaking of the website is happening for end-users who are coming to our website on IE11. We suddenly got thousands of exceptions on Friday after that we had to disable the toolbar.


to answer your question, yes, we are getting errors for non-logged in users.

Thank you. Can you tell me the URL of you repository and website? Also when you say 'breaking' the websites stop completely or do they just receive exceptions?

site url

repository :

we get exceptions in IE 11 that stops the page to render completely.

Thank you, I've passed this to the team and we are investigating. I'll most likely have updates tomorrow.

I was just about to make a similar post. I discovered last week that IE11 was having issues and I finally narrowed it down to the preview script. Based on analytics I can see, I suspect the problems may have started on Friday, July 31.

The symptoms for us include breaking all onMouseEnter and OnClick events.

Repo: gfoaorg

Thank you I've passed this information to the team. :slight_smile: I'll update everyone once I know more.

@luke.seemann @kapil Can you copy and paste and console errors that you are seeing so that we can test this further.

We were not able to reproduce with a test site on IE 11. We can see that the toolbar is not working (errors in console) but it’s not breaking the website itself. But of course our test website is very simple, so it doesn’t match real client cases.

Sure. Here are two test pages.

Without script:
With script:

And here are the console logs I get on /2:

Which is actually unusual … In our production site, we don't get any console errors at all, and components render as expected, but click and hover events just fail silently.

We’re on a NextJS rig. Here are the Typescript files for the test pages I've linked to here. (1.2 KB)

Thank you for the extra information, I've passed it to the team.

Prismic script toolbar script is breaking on IE11 (refer screenshot)

  1. Is it supported on IE11 ?

  2. read a thread saying this issue has been fixed on IE11 . Does this need some activation from Prismic side ?

Looking for a quick response as this is a blocker for us.

Hi Mokriya,

  1. We've just released a new version of the Toolbar and it no longer supports IE11.
    Although it is causing some issues for this browser in terms of functionality in this browser as you've seen and as described above by other users.

  2. This was a fix for an older version of the toolbar, so it's no longer relevant.

If this is causing user IE11 websites to break then we suggest disabling the script for now. If this is stopping you from preview Prismic content, we suggest using a different browser.

We are going to implement a check on our side which will disable the script in IE11 as was already done for IE10, this will at least stop any errors appearing in the console. Once we have done this we will update everyone here.


Hey just an update for everyone. We've have created the fix, we're just testing and waiting for it to be deployed.

This has now been deployed and the Toolbar is now disabled for all Internet Explorer users. This should now not cause any breaking issues for this browser.