Step i) Restart your MacBook Pro and immediately press and hold the SHIFT key. Step ii) Release the key when the login window appears. Enter the correct credentials to log in. Step iii) Reboot your MacBook Pro and resolve the MacBook Pro not booting issue. When your MacBook Pro shuts down, hangs, or restarts in Safe Mode, then repair the Mac. A spare admin user account is useful because it hasn't had changes to its preference files. It also doesn't contain any data beyond what macOS adds when the account is created. Once you have administrative access to your Mac, you can reset your forgotten password and then log out and log back in with your regular account. This happened for me on 10.10.5 and I kept getting the 'cannot connect' message no matter what I tried. The issue for me was that I recently had downloaded and started using a proxy server (Socksharex), and it changed my network setting connection preferences; it kept trying to access the proxy server, even after I had realized that I didn't want the proxy server and deleted it and its app. Macbook air software.