Following can be a different bug, but I hope that this is likely to be the same bug:
1. Open Thunderbird
2. Open account settings *from HUD* (it is needed to open it from HUD and NOT from Thunderbird overview page)
3. Try to expand some dropdown menu (e.g. "Outgoing Server (SMTP)" or "Server Settings / Connection Security").
The same proglem appears. The dropdown men does not expand. Since both Firefox and Thunderbird are Gecko-based and there are similar Ubuntu add-ons, I hope this is related.
Following can be a different bug, but I hope that this is likely to be the same bug:
1. Open Thunderbird
2. Open account settings *from HUD* (it is needed to open it from HUD and NOT from Thunderbird overview page)
3. Try to expand some dropdown menu (e.g. "Outgoing Server (SMTP)" or "Server Settings / Connection Security").
The same proglem appears. The dropdown men does not expand. Since both Firefox and Thunderbird are Gecko-based and there are similar Ubuntu add-ons, I hope this is related.