In Crossover Mac 16.0 trying to use the Steam overlay (shift+tab) in a Win7 or later bottle, or a 64-bit bottle, either won't work or could freeze the game.
There was a compiler hack done years ago to get the Steam overlay working in the default WinXP 32-bit bottle which is no longer available in newer bottle types.
We have a bug on this issue but no timeframe on when it might be fixed. In the meantime if you need to install Steam into a Win7/64-bit bottle to satisfy a game's system requirements you'll want to disable the Steam overlay. In Steam go to the View menu, Settings, In-Game, and uncheck Enable the Steam Overlay while in-game.
