Kernel panic - Mac won't allow me to log in My MacBook Pro is going through some sort of kernel panic, however it is not letting me log in at all. It just keeps restarting and playing the chime music before showing some error code text on the loading screen. Then the cycle repeats. Is there any way to fix this?
Something like that happened to me after upgrading to El Capitan.
The system would only behave "normally" if I started it in safe-mode (https://support.apple.com/en-us/HT201262)

So I tried restarting it again in verbose mode (https://support.apple.com/en-us/HT201573) and just before the "panic" message, there was a reference to a kernel extension (kext) for a very old program that I didn't even remembered installing...

I fixed it by restarting the system again in safe-mode and unloading that kext.
The next boot, the system began again working ok...

HTH