I'm developing an extension, and first noticed this issue myself over a month ago. It has been present across at least two stable-channel releases (including 53.0.2785.143). Also witnessed in Canary.

This bug is very easy to replicate. All you need is an extension whose popup overflows vertically. The frequency of the bug seems to be tied to how complex the rendering is (the number of elements, the number of style rules, etc.). So, frequency can be between 5% and 50%, depending on the complexity of the popup.

When the bug does occur, the popup can only be scrolled by dragging the scrollbar. No other scroll method seems to work (arrow keys, scroll wheel, scrollbar arrow buttons).

There is, however, a solution (that took me a long time to discover). Simply add the following element to the DOM:

<div style="position:fixed"></div>

Presumably, it doesn't have to be an empty <div> with an inline style, just a fixed-position element, though I haven't tested this.

I have attached a 1 KB extension that demonstrates the bug. To replicate the bug:

1. Install extension.
2. Open popup.
3. Attempt to scroll (with scroll wheel, arrow keys, or by using the scrollbar's arrow buttons).
4. If window scrolls successfully, close popup and goto step 2.

It should take no more than 20 attempts to replicate the bug.

To fix the bug:

1. Open dev tools.
2. Navigate to the Elements panel.
3. Insert <div style="position:fixed"></div> as HTML into the body.
4. Attempt to scroll.

Deleted: chromebug.crx 1.2 KB

chromebug.crx 1.2 KB Download

Almost 2 months and nobody (besides another user) has even confirmed this yet? This issue is super annoying, especially since it's likely a really easy fix. Somebody? Anybody?

I can't repro in 53 or canary.
To locate the issue developers need to know exactly when it first occured.
Can you manually find the exact Chrome snapshot where the problem appeared (the previous snapshot should not have this problem) using https://commondatastorage.googleapis.com/chromium-browser-snapshots/index.html ?
The snapshot number range may be obtained via https://omahaproxy.appspot.com/ e.g. 51.0.2704.84 is 386251 and 53.0.2785.143 is 403382

Thank you for responding. Unfortunately, I'm not knowledgeable enough to pinpoint a "snapshot". I can tell you that I first encountered it after the update where bookmark/extension hover/focus states where "modernized" (animated, I guess). The two may be completely unrelated, but that's when the bug appeared. As for reproducing, the above test .crx reproduces the issue pretty consistently. In fact 3 out of the first 5 attempts at opening the popup and scrolling "page down" failed (thumb is still draggable). 

As I, and the other poster have stated, the issue occurs intermittently. It can and will scroll successfully many times in a row, but it freezes at least 5-10% of the time. I'm not sure what factors contribute to this bug, but sometimes it occurs much more frequently. 

I should also mention for testing purposes, that testing the popup multiple times on the same page-load seems to be unhelpful. Once it succeeds or fails, it seems to remain that way until a new page-load.

Issue has not been modified or commented on in the last 365 days, please re-open or file a new bug if this is still an issue.

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