Fatal error

Hello!
I updated wordpress to the latest version and got the following error:

Fatal error: Cannot redeclare url_is_accessable_via_ssl() (previously declared in /home/…./wp-includes/functions.php:2862) in /home/…/wp-includes/deprecated.php on line 3493

Throw FTP I change function.php to the original and it starts working for several minutes.
Here I read the solution to play with active theme and plugins. Treid it but did not help.
Please worrdpress guru give the advise what to do with this error disapear.
Great thanks in advanced.