Starting Tower after an update
In some rare cases, the updater cannot properly quit the "old" Tower app as you hit the "Install and Relaunch" button of the updater. This will prevent the new Tower version from starting up, showing just the main menu, but no window.
In this case, you need to quit the old Tower process yourself by starting the Task Manager, search for "Tower" and quit all processes that show up selecting "End Task" in the context menu. A reboot of your machine will also work.
After terminating the old process, Tower should start up normally again.