Title: Version 4.5.2 causing PHP errors Last modified: August 31, 2016 --- # Version 4.5.2 causing PHP errors * [bhambob](https://wordpress.org/support/users/bhambob/) * (@bhambob) * [10 years ago](https://wordpress.org/support/topic/version-452-causing-php-errors/) * Just installed 4.5.2 and now we are receiving incessant PHP errors. No changes have been made to our website. We have had our own session management for ages but now when we get to the session_start() we get the following error: * session_start(): Cannot send session cookie – headers already sent by (output started at /var/www/html/wp-includes/class.wp-styles.php:237) * This NEVER occurred before we upgraded from 4.5 to 4.5.2. Viewing 10 replies - 1 through 10 (of 10 total) * Moderator [t-p](https://wordpress.org/support/users/t-p/) * (@t-p) * [10 years ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374114) * Try deleting the old wp-includes folder and replace it with a fresh copy. Download a fresh copy of the WordPress .zip file to your computer, unzip it, and use that to copy up wp-includes folder. * Thread Starter [bhambob](https://wordpress.org/support/users/bhambob/) * (@bhambob) * [10 years ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374174) * And I was so hopeful… Before making any change to production I did a file compare between the class.wp-styles.php installed and the one I extracted from a downloaded zip file. They are identical. Other ideas? * Thread Starter [bhambob](https://wordpress.org/support/users/bhambob/) * (@bhambob) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374309) * We are getting pummeled by this problem, hundreds and hundreds of errors are raised each day. This was never an issue before we moved from 4.5 to 4.5.2. * Thread Starter [bhambob](https://wordpress.org/support/users/bhambob/) * (@bhambob) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374348) * Can I get some help with this or not? If not, how do I back up to version 4.5? * [codejockey](https://wordpress.org/support/users/codejockey/) * (@codejockey) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374349) * Here is a good youtube video on how to go back to a previous version. I would recommend backing everything up before making changes. * [How to downgrade WordPress…](https://www.youtube.com/watch?v=_lX3E-qIpJM) * [codejockey](https://wordpress.org/support/users/codejockey/) * (@codejockey) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374350) * Or, if you hosting provider makes nightly backups, you could ask them to restore to a previous backup when the version was still 4.5. * Thread Starter [bhambob](https://wordpress.org/support/users/bhambob/) * (@bhambob) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374351) * Thanks. Will check it out. * So, apparently version 4.5.2 introducing problems is of no concern. I mean, really, we’re supposed to never update again? * [kmessinger](https://wordpress.org/support/users/kmessinger/) * (@kmessinger) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374352) * > We have had our own session management for ages * And that is probably the problem. Going back to a previous version may work but it is not a solution. * You can also check here, [https://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F](https://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F) * Thread Starter [bhambob](https://wordpress.org/support/users/bhambob/) * (@bhambob) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374353) * There is a built-in WP session manager? I didn’t see anything in the WP functions. Should I schedule an optometrist appointment? * I looked at the suggested link, and am already familiar with what can lead to the error. In this case, though, the error began to occur with the install of 4.5.2, and the echo statement at /var/www/html/wp-includes/class.wp-styles.php: 237 is where the first output character is emitted. Then I come along later with a session_start() command in a theme functions file, which leads to the error. * Thread Starter [bhambob](https://wordpress.org/support/users/bhambob/) * (@bhambob) * [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374354) * With my fingers crossed… I *think* I may have successfully addressed the problem. I took a look [here](http://silvermapleweb.com/using-the-php-session-in-wordpress/) and moved my session_start upstream, into an init action. In the 45 minutes that have elapsed since this change, none of the aforecited errors have occurred. More importantly, the objective for the sessions to being used to begin with seems to have not been compromised. Viewing 10 replies - 1 through 10 (of 10 total) The topic ‘Version 4.5.2 causing PHP errors’ is closed to new replies. * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/) * 10 replies * 4 participants * Last reply from: [bhambob](https://wordpress.org/support/users/bhambob/) * Last activity: [9 years, 12 months ago](https://wordpress.org/support/topic/version-452-causing-php-errors/#post-7374354) * Status: not resolved ## Topics ### Topics with no replies ### Non-support topics ### Resolved topics ### Unresolved topics ### All topics