1416609 - Vertical scrollbar slider invisible on some web sites

Status: RESOLVED DUPLICATE of bug 1408701

(Core :: Widget: Cocoa, defect)

Description

[owenw4rd]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:56.0) Gecko/20100101 Firefox/56.0
Build ID: 20171024165158

Steps to reproduce:

Open Firefox 56.0.2 (64 bit) in safe mode on a MacBook Pro (Retina, 13-inch, Mid 2014) running macOS High Sierra 10.13.1 (17B48)
Go to example web site: https://forum.davidicke.com/


Actual results:

The web page is vertically scrollable, but the vertical scroll bar is invisible.


Expected results:

Vertical scroll bar should be visible.
This only happens on some web sites.
Doesn't happen on FF running under Windows 10.

Comment 1

[owenw4rd]

I found a work-around:

Under System Preferences|General, set Show Scroll Bars: When Scrolling forces the scroll bar to appear after scrolling the mouse wheel or trackpad.

Setting it to Automatic or Always leaves the scroll bar invisible.

Comment 2

[Kohei Yoshino]

That's the default behaviour of macOS apps. As you said, you can/should change it in the system settings.

Comment 3

[owenw4rd]

No, the scroll bar is visible on the Safari browser when the sysyem scroll bar setting is Always!

Comment 4

[owenw4rd]

Don't be so quick to close the bug. Try to reproduce it first.

Comment 5

[owenw4rd]

Clarification: 

When I said the vertical scroll bar is invisible, I meant the slider. The scroll bar itself was visible, but the slider was invisible.

Comment 6

[Kohei Yoshino]

Okay, I can understand & reproduce the issue now.

Comment 7

[Stephen A Pohl [:spohl] (OOO until 2/27)]

Fixed in Firefox 57.