VPN Details Windows Appears at Startup (Login)
This is related to Tunnelblick Launches at Startup (Login).
Some users see Tunnelblick's VPN Details window appear when they log in or start up their computer.
(It is not the same as seeing Tunnelblick's "startup window", which appears briefly and then disappears when Tunnelblick is launched. That may be disabled on the "Appearance" panel of the VPN Details window.)
It can happen if the user has added Tunnelblick to the "Login Items" (either via the "Open on Login" Dock option or in System Preferences). Tunnelblick has its own mechanism for launching itself at login (see Why and How Tunnelblick Doesn't Use Login Items), and if the user adds Tunnelblick to the Login Items, it may cause Tunnelblick to be launched twice.
The second launch causes Tunnelblick to display the VPN Details window. (Tunnelblick is designed this way so that if Tunnelblick is running, clicking on Tunnelblick in the Dock, or double-clicking it elsewhere, will show the VPN Details window.)
Note that the VPN Details window may not always appear. If Tunnelblick is not running when you log out, Tunnelblick will not launch itself at the next login. In that situation if Tunnelblick is a "Login Item", it will be launched once and appear in the menu bar.
Fixing the Problem
The way to prevent the VPN Details window from appearing is to remove Tunnelblick from the Login Items by one of two methods:
If the VPN Details window is appearing when you log in and Tunnelblick is not a Login Item, ask for help on the Tunnelblick Discussion Group.