Created an attachment (id=8561) [details]
Screen capture

After the update I am able to see only one row of all the bookmarks I had.

Created an attachment (id=8562) [details]
4.13 prerelease 3

Quick fix version

Added overflow: visible to the toolbar to force proper wrapping. Tested on
Windows 7 64bit

Working on my Mac OS X Mojave 10.14.1

(In reply to comment #1)
> Created an attachment (id=8562) [details] [details]
> 4.13 prerelease 3
> 
> Quick fix version
> 
> Added overflow: visible to the toolbar to force proper wrapping. Tested on
> Windows 7 64bit
> 

*** Bug 26613 has been marked as a duplicate of this bug. ***

Created an attachment (id=8563) [details]
4.13 prerelease 6

With a slightly different solution: I removed the class .chromeclass-toolbar
from the QuickFolders toolbar instead of force-changing the styling. Hopefully
this won't have any adverse side effects (please test all tab menu
functionality to be sure)

Same problem on Windows X, TBird version 60.3.2 32-bit.

Kind of a show stopper.

Working in MacOS Mojave 10.14.1

(In reply to comment #4)
> Created an attachment (id=8563) [details] [details]
> 4.13 prerelease 6
> 
> With a slightly different solution: I removed the class .chromeclass-toolbar
> from the QuickFolders toolbar instead of force-changing the styling. Hopefully
> this won't have any adverse side effects (please test all tab menu
> functionality to be sure)
> 

*** Bug 26614 has been marked as a duplicate of this bug. ***

*** Bug 26615 has been marked as a duplicate of this bug. ***

(In reply to comment #5)
> Same problem on Windows X, TBird version 60.3.2 32-bit.
> 
> Kind of a show stopper.
> 

Attachment (id=8563) fixed it for me. 
Thanks.

I confirm 4.13 prerelease 6 works fine on Windows 10 with Thunderbird 60.3.2
(32bit).

Thank you for your *great* job!

(In reply to comment #4)
> Created an attachment (id=8563) [details] [details]
> 4.13 prerelease 6
> 
> With a slightly different solution: I removed the class .chromeclass-toolbar
> from the QuickFolders toolbar instead of force-changing the styling. Hopefully
> this won't have any adverse side effects (please test all tab menu
> functionality to be sure)
> 

That's a fix for me, thanks a heap!
Brian on Win10

*** Bug 26617 has been marked as a duplicate of this bug. ***

Created an attachment (id=8565) [details]
4.12.1 Official Release

This is the official release including the bugfix. It will appear on
http://addons.thunderbird.net/ shortly.

*** Bug 26618 has been marked as a duplicate of this bug. ***

Official Release of 4.12.1

Thank you for fixing!!

I am using Windows 10 and also have only 1 line of tabs showing.

(In reply to comment #17)
> I am using Windows 10 and also have only 1 line of tabs showing.
> 

Thanks - the easiest way to update is now using the Thunderbird built in
function "Check for Updates" in Update manager. there is a menu button on the
top right beside the search box for this - it will automatically download and
install 4.12.1 for you.

(In reply to comment #18)
> (In reply to comment #17)
> > I am using Windows 10 and also have only 1 line of tabs showing.
> > 
> 
> Thanks - the easiest way to update is now using the Thunderbird built in
> function "Check for Updates" in Update manager. there is a menu button on the
> top right beside the search box for this - it will automatically download and
> install 4.12.1 for you.
> 

...unless, of course, you already have installed a higher-numbered version,
such as the 4.13pre6 in attachment #8563 [details].

(In reply to comment #19)
> (In reply to comment #18)
> > 
> > Thanks - the easiest way to update is now using the Thunderbird built in
> > function "Check for Updates" in Update manager. there is a menu button on the
> > top right beside the search box for this - it will automatically download and
> > install 4.12.1 for you.
> > 
> 
> ...unless, of course, you already have installed a higher-numbered version,
> such as the 4.13pre6 in attachment #8563 [details] [details].
> 

That's right. In case the auto-update doesn't work (if you have already a
higher number installed or there are problems with contacting the update
service) the manual route is:

1) open the Add-ons Manager in Thunderbird
2) drag the attachment link above  (4.12.1 Official Release) ito the Add-ons
Manager.

(alternatively, right-click the attachment link, save as file, and then drag
the file into the Add-ons Manager)

the drag and drop should also work from 
https://addons.thunderbird.net/thunderbird/addon/quickfolders-tabbed-folders/

by dragging the green "download now" button into the Add-on Manager.

Apart from updating, this is the quickest way once you get your head around it.