Rated 5 out of 5 stars

by Tony Mechelynck on Nov. 27, 2013 · permalink

When many lightweight themes are installed, this add-on makes managing them extremely easy, including (but probably not limited to):
-- telling lightweight themes and complete themes apart from each other (in the Add-on Manager they appear interspersed in a single list; this extension opens a page listing only lightweight themes);
-- checking how a lightweight theme other than the current one would look like if it were enabled (by hovering the mouse over the thumbnail);
-- finding which lightweight themes were installed from an obsolete URL (such as getpersonas.com) and need to be refreshed if they are to be used again in the future. (These "obsolete" add-ons are shown in the LWTM without a thumbnail.)
---- WARNING: Reinstalling the same lightweight theme, but from a working URL (such as addons.mozilla.org), which can be done by means of the link in the LWTM page, won't make the obsolete entry disappear; and AFAICT there is no [_Uninstall_] button for lightweight themes. AFAIK the only way to uninstall a lightweight theme consists of removing the corresponding {...} entry, with one (but not both) of the separating commas around it, in the value of the preference lightweightThemes.usedThemes in about:config. Since that value can be extremely long, especially if many lightweight themes are installed, I recommend to do this as follows:

1. In about:config, find the preference lightweightThemes.usedThemes, right click it, and select "Copy Value";
2. Paste the value into your favourite text editor and edit it there;
3. Copy the new value (as it appears in your editor) to the clipboard;
4. in about:config, double-click lightweightThemes.usedThemes (the old value will appear, selected, in an input box in a popup) then click Ctrl+V (to paste the new value which you copied at step 3) then click the [_OK_] button at the bottom of the popup. If you then refresh about:addons or the LWTM (or both) you should notice that the unwanted entry has disappeared.

P.S. Of course, in Thunderbird, about:config is the "Config Editor" which can be opened by means of a button in the "Advanced" preferences.