Created attachment 104220 [details] Compose window With the latest update to 5.9.2, my Thunderbird started looking terrible. I got solid black lines as widget separators and my conversations (Thunderbird Conversations plugin) got an ugly gray background with a white rectangle instead of a fully white background. I attached screenshots to depict better what I mean. Everything worked fine in 5.9.0 (and probably 5.9.1). Native GTK applications look fine. Firefox seems to work as well, but Thunderbird looks terrible. Using Plasma 5.9.2 on Arch Linux.
Created attachment 104221 [details] Conversation, note the gray background around the white rectangle, the reply and forward buttons also used to have white background
This has nothing to do with the 5.9.2 update, this is because thunderbird is now compiled with gtk3 instead of gtk2
Possible that it got updated as well. Wasn't exactly sure what caused the problem. It's still an issue, though.
Fixed now!