Cinema 4D crushes everytime I click the middle mouse button.

[Sam Treadway]

First, Send a crash log to Maxon so they are aware of it.
If you are using special mouse drivers, make sure you update/reinstall them.
If that fails then try reinstalling C4D again.
If it still crashes, then create a new user profile on your system to troubleshoot. In that new profile don’t allow any other background apps to autostart. Just use this clean user profile to test. If C4D doesn’t crash then something loading in the background in your original user profile is causing the problem. If the problem still persists in the new user profile then there is likely an issue with hardware drivers or the OS.