I got this error when I tried to open my dashboard after doing an automatic Wordpress update. My website is still showing up normally; I just can't access the dashboard to work on it. Previous answers to the same problem elsewhere online suggested clearing the cache and manually updating Wordpress using FTP. I've tried both of these things, but they didn't work. I can't find any other suggestions, so I'm asking here. How can I fix this problem? Please try to be detailed in your instructions, as I am just a layperson with a website and not a developer. Thank you!
I think you first need to verify whether a plugin or theme is causing the problem.
Temporarily rename the
wp-content/plugins folder to something else, then access the admin panel. If the problem does not reoccur, recreate the
wp-content/plugins folder, then move plugins' folders in there in small groups to determine a suspect. You may need to activate those plugins.
If you can get to the admin page with plugins disabled, do a WP core update via the Updates page. Then start eliminating plugins.
If the problem is still there with
wp-content/plugins folder renamed, rename non-default themes (in
wp-content/themes) folders (the ones that aren't 'twenty-something'). That will cause your theme to default to the WP-supplied one. Get into the admin page and do a WP core update.
Then restore themes and activate them as needed until you find the culprit.
I suspect a plugin before a theme. And know that this will cause your site to be a bit 'goofy' because plugins are disabled. But that is what I would do.
Here are a few options, mostly to identify where the function is:
If you have SSH access you can login and go to your website's directory (eg.
cd /path/to/public_html/then do:
grep -R "wp_raise_memory_limit" *... this should locate where the function is being called that doesn't exist.
Similarly, but without SSH, download the entire site via FTP (yes a bit of a pain to wait, but you could do it a bit at a time also, start with the
/wp-content/plugins/folder)... then use a program such as Textpad to Search -> Find in Files for the text
wp_raise_memory_limitwithin the files downloaded locally.
So guess what? I just tried downgrading to the previous version of Wordpress, and that fixed it! I guess there must be some sort of bug with the latest version. I will definitely make sure to back up my website now though, just in case. Thanks everyone for trying to help!