Something happened today - I cannot browse through accounts/folders as usual, they are not refreshed on the right tab, only the welcome screen.I can open the letters list by rightclicking and opening in new tab, but it also works not fine. The button for creating letter doesn't work at all! The same is for "reply", "forward" and other buttons. I can't delete messages etc... Rebooting notebook, or reinstalling Thunderbird didn't help. I really need help, what could be the reason for this?