I downloded GM seed of OS X 10.11, after downloading hit start button, after installation it auto reboot, and i signed in my laptop password, saw progress bar went to 50%, and the screen had a big flash, then went to black. Tried safe mode, after signed in with my account password, laptop has been frozen at 50% progress bar.
Hi JT,
What you've described is very similar to others that had 3rd party kernel extensions (kexts) cause El Capitan to crash on boot because of the way it's new security measures fail to handle them. I'm happy to help see exactly which ones are causing the issue in your case.
Since I think you must have FileVault installed, the first thing is to unlock your partition, so please boot into Recovery Mode (cmd+R). Open Disk Utility from Recovery Mode's central menu and select the El Capitan partition and unlock it with you password.
The next step is to use Terminal to find the kexts and it will be easier to post the commands to do that if I know the name of your El Capitan partition. Is it still called "Macintosh HD"? (It will be unless you renamed it).
Max.