HELP!!!! El Capitan won't start! Error message! Help!!

[ksechrist]

Updated my MacBook Pro to El Capitan and when I restarted it and log in on the home page (picture attached) I get this overlayed black-white error text and then it restarts and the whole thing happens over and over again. Tried resetting pram but nothing. Help!!!!

 

[dianeoforegon]

If you look at the text it says "Mac OS Version - Not yet set"

Looks like you had an incomplete upgrade to El Capitan. Do you have a backup you can boot from to reinstall El Capitan?