"Problem repeatedly occurred" error in Safari

Problem Description: 

When page is scrolled too fast, error appears saying "problem repeatedly occurred" and page reloads. This is limited to only newer iOS versions and certain themes and animation configuration. Also rarely happens in "Facebook in-app browser" 


This issue that popped up a few times over the last six months. We have been looking at the root cause, and I must say it's pretty hard to debug. When the crash occurs, the page gets reloaded and no errors or indications what may be wrong are given - console gets erased during the crash.

It also happens only on some themes. This error also tends to affect only on some iOS versions, I have access to two iPhone XSs, one with newest iOS and one with 13.4.1 - funny enough, this bug only happens on the new iOS in Safari. After further testing, I was able to reproduce the issue also on "Facebook in-app browser" on iOS.

So my debug approach was to create a minimal version of the Scrollsequence Javascript and try to find, what may cause this. And to my surprise, even when I have re-written the "minimal" script using a different coding approach (javascript class instead of loops) the issue still occurred.

Currently I believe, that there is some kind of bug in Safari that throws this error and reloads the page, when the page is taking up too much resources, or it may be related to performance/graphics issue when painting/decoding large images on a full-screen canvas. Also this issue only occurs when scrolling at high speeds.


From version 1.3.0 this bug was resolved by limiting the scroll exit velocity. If it's greater then 2500px/s the animation completes instantly and frees up resources. 

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