ਜਨ 29, 2018 ਤੇ Jarek Bialkowski (Developer) ਵੱਲੋਂ · ਪਰਮਾਲਿੰਕ

The theme has nothing to do with opening any windows. It just styling them. I just installed Thunderbird 52.6 as well and I don't see any issues till now. Please disable all your additional plugins and check again. I need more details to track your issue. Which OS are you using? Could you make a screenshot and mark the places where you are clicking?