Maybe the theme you chose has not been correctly configured to work with the TB version you are using; maybe it worked on older versions and the author has not updated it.

What theme are you talking about ? Have you reported the problem to the author of the theme ?

Just had an idea, perhaps you do not have the Title Bar enabled and the author designed it to work with title bar enabled.this used to be enabled by default, but recent versions disabled it by default. Try this: 'Tools' > 'Options' > 'Advanced' > 'General' tab or 'Menu icon' > 'Options' > 'Options' > 'Advanced' > 'General' tab

• Click on 'Config Editor' button - it will tell you to be careful :)
• In top search type: title
• look for this line: mail.tabs.drawInTitlebar
• If Value = 'True', double click on the line to toggle the 'True' to 'False'
• close Config Editor window - top right X
• click on 'OK' to save and close Options

Please report back on whether enabling the 'Title bar' helped.

Using the Config Editor solved the problem. Thanks for the help.

I am now trying to add a theme to my Firefox browser (Ver 43.0.4) and the same thing is happening (ie, covering up the minimize and stop buttons in the upper right corner).

Good to hear the info helped to resolve the thunderbird issue. Technically Firefox issues should really be asked in the Firefox forum. However, no matter - I located this info which could assist you. It is probably a similair issue regarding the Title Bar, so I would start with making sure that is enabled first.

• https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars#w_turn-on-the-title-bar-menu-bar-or-bookmarks-toolbar

Thank you Toad-Hall. It worked like a charm.

Good to hear all is now working properly.