Place near the Spotlight icon Checkbox
Early versions of Tunnelblick placed the Tunnelblick icon near the Spotlight icon on the right side of the menu bar.
Later versions include a checkbox to allow the user to control the icon placement.
In macOS Sierra, the user may move the Tunnelblick icon and the other icons on the menu bar by dragging while holding down the "Command" key, so there is no need for this checkbox and it is disabled.
On some other recent versions of macOS, the feature does not work properly if the user has selected "Displays have separate spaces" in the "Mission Control" System Preferences. This usually affects only systems with multiple displays, but it also affect some systems without separate displays. The checkbox is disabled in such systems.
In some situations, Tunnelblick does not know that the feature will not work, and so the checkbox is enabled and the user is warned if the setting might cause problems.