# "Unexpected error" when closing cell

**URL:** <https://talk.observablehq.com/t/unexpected-error-when-closing-cell/3101>\
**Category:** Feedback\
**Created:** [April 19, 2020, 4:57am UTC](https://talk.observablehq.com/t/unexpected-error-when-closing-cell/3101 "2020-04-19T04:57:17Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![jrus](https://yyz2.discourse-cdn.com/flex030/user_avatar/talk.observablehq.com/jrus/32/586_2.png) [@jrus](https://talk.observablehq.com/u/jrus)\
**Post date:** [April 19, 2020, 4:57am UTC](https://talk.observablehq.com/t/unexpected-error-when-closing-cell/3101/1 "2020-04-19T04:57:17Z")

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Whenever I toggle any cell closed here in Safari 12.0, notebooks are immediately breaking and taking me to an error view which looks like:

 ![Screen Shot 2020-04-18 at 9.56.10 PM](https://canada1.discourse-cdn.com/flex030/uploads/observablehq/original/2X/a/ab4f52f7d183da19b1771c5450f2de3c63a91f3b.png)

Here’s what the browser console shows:

 ![Screen Shot 2020-04-18 at 9.53.11 PM](https://canada1.discourse-cdn.com/flex030/uploads/observablehq/original/2X/8/806a1279d24a586c10df3103edb0fb7494f74bc3.png)

Needless to say, this makes Observable pretty unusable right now in this browser.

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**Author:** ![mbostock](https://yyz2.discourse-cdn.com/flex030/user_avatar/talk.observablehq.com/mbostock/32/9_2.png) [@mbostock](https://talk.observablehq.com/u/mbostock)\
**Post date:** [April 19, 2020, 5:14am UTC](https://talk.observablehq.com/t/unexpected-error-when-closing-cell/3101/2 "2020-04-19T05:14:57Z")

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Apologies. This bug only occurs in older browsers that don’t support IntersectionObserver. I’ll deploy a fix shortly.

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**Author:** ![jrus](https://yyz2.discourse-cdn.com/flex030/user_avatar/talk.observablehq.com/jrus/32/586_2.png) [@jrus](https://talk.observablehq.com/u/jrus)\
**Post date:** [April 19, 2020, 5:22am UTC](https://talk.observablehq.com/t/unexpected-error-when-closing-cell/3101/3 "2020-04-19T05:22:54Z")

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I should probably get around to upgrading the operating system on this particular computer at some point…

Thanks, Mike!

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**Author:** ![mbostock](https://yyz2.discourse-cdn.com/flex030/user_avatar/talk.observablehq.com/mbostock/32/9_2.png) [@mbostock](https://talk.observablehq.com/u/mbostock)\
**Post date:** [April 19, 2020, 5:25am UTC](https://talk.observablehq.com/t/unexpected-error-when-closing-cell/3101/4 "2020-04-19T05:25:27Z")

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Fix deployed. Thanks for the report!

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**Author:** ![jrus](https://yyz2.discourse-cdn.com/flex030/user_avatar/talk.observablehq.com/jrus/32/586_2.png) [@jrus](https://talk.observablehq.com/u/jrus)\
**Post date:** [April 19, 2020, 5:31am UTC](https://talk.observablehq.com/t/unexpected-error-when-closing-cell/3101/5 "2020-04-19T05:31:25Z")

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I’m glad I just went to look at my cell at [https://observablehq.com/@jrus/misc](https://observablehq.com/@jrus/misc) which imports an intersection observer polyfill, because apparently loading it from bundle.run was broken, so likely several of my notebooks have been temporarily broken.

Luckily the “global leak” import style seems to work still.