[Affected versions]: - Firefox 53 beta 7 - latest Developer Edition 54.0a2 - latest Nightly 55.0a1 [Affected platforms]: - macOS 10.12.2 - Ubuntu 16.04 32bit - Windows 10 64bit [Steps to reproduce]: 1. Open Firefox, install 5 or more light themes https://addons.mozilla.org/en-US/firefox/themes/ 2. Visit about:addons#appearance and enable a compact theme. 3. Enter Customize, select Themes and pick one 4. Click Themes again [Expected result]: - Compact theme (being the second last theme used) is still displayed in My Themes list under Default and the actual selected theme. [Actual result]: - Compact theme is missing from My Themes list. [Regression range]: - This is not a recent regression, it also reproduces on old Nightly from 2017-01-15 when compact themes was introduced by default in Nightly. [Additional information]: - Not sure if this is intended or not, but I think those themes should behave like other light themes. Once I have many themes installed, I can only enable the compact theme from about:addons#appearance and other light themes can be enabled from customize.
How many is "many"? is it exactly 5?
(In reply to Jeff Griffiths (:canuckistani) (:⚡︎) from comment #1) > How many is "many"? is it exactly 5? Just to be extra clear with the [Additional information]: - If one installs exactly 4 lightweight themes and open My Themes from customize, the 5th will be one of the compact themes (Default theme not included) and the second compact theme will not be displayed. - Installing a 5th lightweight theme will make compact themes disappear from My Themes from customize making them accessible only from about:addons#appearance. - When enabling any of the compact themes (from about:addons) it will be displayed in My Themes until any of the previously 5 lightweight themes is enabled. - Once this happens, the previously enabled compact theme will disappear from My Themes dropping down to 6th and 7th installed themes, which are not displayed. Basically whenever a lightweight theme is enabled, the compact themes are always the last two from the list, even though one of them was previously used. I hope this answers your question. Let me know if can provide any additional information.