White page of death after auto update to 4.6

It seems like alot of people are having problems with the 4.6 update, I would try the first fix here:[Offsite link removed – please do not post links to proprietary sites] Even though that is not the problem your having it could be a fix.

it seems like alot of people are having problems with the 4.6 update

You think? I’m seeing very few issues considering that this was a major core upgrade.

@sloow: Try checking your site’s error logs for a more specific error message. Your hosts should be able to help you accessing your site’s error logs.

After the 4.6 update, all! the content of my posts vanished. All I can see is the title. Wonder if this is related to WP_Term_Query and WP_Post_Type

A new WP_Term_Query class adds flexibility to query term information while a new WP_Post_Type object makes interacting with post types more predictable.

So I am getting this message. It’s not the only one, but it is repeating a lot:

[Thu Aug 18 00:26:29.612329 2016] [:error] [pid 861602] [client xxxxxx:] PHP Fatal error: Cannot redeclare the_post_thumbnail_caption() (previously declared in /home/domain/domains/mydomain.com/public_html/artsite_wp/wp-includes/post-thumbnail-template.php:244) in /home/domain/domains/mydomain.com/public_html/artsite_wp/wp-content/themes/artpress-child/functions.php on line 275

also this:
[Thu Aug 18 02:27:47.049965 2016] [:error] [pid 896586] [client xxxxxxx] PHP Strict Standards: Declaration of Walker_Page::end_lvl() should be compatible with Walker::end_lvl(&$output) in /home/domain/domains/mydomain.com/public_html/artsite_wp/wp-includes/classes.php on line 594

@borag: This is not your topic. If you require assistance then, as per the Forum Welcome, please post your own topic.

@sloow: The first error suggests that there’s a problem with your child theme. Try switching to the default theme automatically by renaming:

wp-content/themes/artpress-child

to:
wp-content/themes/artpress-child-old

using FTP or whatever file management application your host provides.

Seems to be an issue with your theme. Someone else encountered it here:
https://www.ads-software.com/support/topic/46-has-crashed-my-site?replies=14

As it appears to be a commercial theme, you’ll need to get support from the theme’s developers https://flexithemes.com/members/?support=true

renaming artpress-child Doesn’t seem to have any effect. There are a lot of custom pages in there however.

Any new/different entries in your error_log after making the change?

Doooh .. looking at the wrong end of the error log…

[Thu Aug 18 10:43:05.954189 2016] [:error] [pid 1003225] [client 70.24.xxxxx001] PHP Fatal error: Call to undefined function require_wp_db() in /home/lux/domains/mydomain.com/public_html/artsite_wp/wp-settings.php on line 211

That sounds very much like a borked upgrade. Do you have an option to roll back to the previous version of WordPress in Softaculous?

I was probably backing it up while it was upgrading.

Well, that could possibly have created some issues. Try re-uploading all files & folders – except the root wp-config.php & .htaccess files and the wp-content folder – from a fresh download of WordPress. Make sure that you delete the old copies of files & folders before uploading the new ones.

It looks like there’s the last 20 versions I will attempt a restore

Once you’ve managed to roll back to the last version, try deactivating all of your plugins and switching to the 2016 theme before upgrading again.