Update 4.8.1 invalid callbacks

I have also been seeing the same set of warnings 353 inparticular!
I am Also having MASSIVE issues, been through the fix instructions but still no luck.

I have stripped the site back to just one meta box using a custom taxonomy which outputs nothing but the array on the front end.

All it spits out is the warning, no array, i’ve now burnt a day trying to fix it so have now rolled everything back to the working version(7.8.3)

Thanks so Much Tran! The issue is fixed, I really appreciate it. just for knowledge sake, would you mind posting the specific syntax error?

Oh no! I’m now not even able to get into my admin page, I’m receiving this error message:

Warning: Cannot modify header information – headers already sent by (output started at /home3/lindaeee/public_html/wp-content/plugins/meta-box/inc/functions.php:2) in /home3/lindaeee/public_html/wp-includes/pluggable.php on line 1228

Can anyone give me some advice? I am not even sure how I could go back in to deactivate the plugin.

Also, when my site first loads, I receive the same warning at the top of the page and the site does not load. When I reload the site, however, everything comes out find (though I cannot access my admin page through it).

Any help is appreciated!!!
(my site: https://withoutanumbrella.com)

@tburnes: It’s actually the ‘validation’ rule. I don’t remember exactly the line ??

@tango3: please update to 4.8.2 which has a better backward compatibility. Do you register meta boxes for the admin area only?

@lindaeee: please remove the plugin via FTP, then re-install it.

Thanks Tran, I will give 4.8.2 a blast later today on a copy of the site.
I am using meta box to populate a custom post type in admin with fields, many of which are custom taxonomies checkbox lists.

Just updated to 4.8.2 from 4.7.3 with no problems, no missing fields!
@tran, I doff my cap to you sir, Meta box is back to being my favorite plugin!

Thank you @tran — I was able to deactivate my plugins and deleted Meta Box from the WordPress plugins, then installed 4.8.2. I am still getting the same errors and am still unable to view/upload media. I am currently working with the plugin deactivated so I can work with media, but this error message is appearing on my site: Fatal error: Call to undefined function rwmb_meta() in /home3/lindaeee/public_html/wp-content/themes/loma/includes/admin/theme-js.php on line 112

@lindaeee: Can you please send me the theme for testing via the Contact Form at https://metabox.io/contact?

Thanks