500 Error on Post Pages Without Yoast Glue Plugin

Here is our latest php error from our log

[13-Dec-2018 12:48:44 UTC] PHP Fatal error: Uncaught Error: Call to undefined method Sabberworm\CSS\CSSList\Document::splice() in /home/petroleucarlisle/public_html/wp-content/plugins/amp/includes/sanitizers/class-amp-style-sanitizer.php:1713
Stack trace:
#0 /home/petroleucarlisle/public_html/wp-content/plugins/amp/includes/sanitizers/class-amp-style-sanitizer.php(1451): AMP_Style_Sanitizer->transform_important_qualifiers(Object(Sabberworm\CSS\RuleSet\DeclarationBlock), Object(Sabberworm\CSS\CSSList\Document))
#1 /home/petroleucarlisle/public_html/wp-content/plugins/amp/includes/sanitizers/class-amp-style-sanitizer.php(1252): AMP_Style_Sanitizer->process_css_declaration_block(Object(Sabberworm\CSS\RuleSet\DeclarationBlock), Object(Sabberworm\CSS\CSSList\Document), Array)
#2 /home/petroleucarlisle/public_html/wp-content/plugins/amp/includes/sanitizers/class-amp-style-sanitizer.php(990): AMP_Style_Sanitizer->process_css_list(Object(Sabberworm\CSS\CSSList\Document), Array)
#3 /home/petroleucarlisle/public_html/wp-content/plugins/amp/includes/sanitizers/cl in /home/petroleucarlisle/public_html/wp-content/plugins/amp/includes/sanitizers/class-amp-style-sanitizer.php on line 1713

Same issue here, all our AMP Pages on all sites are broken.

@guardian88 @mexl Thanks for reporting. It seems you may have CSS that we haven’t encountered before, and it is causing this exception. I’ll try to replicate the issue and give you a patch to test.

@guardian88 @mexl Did you install the plugin via www.ads-software.com or via GitHub?

The error says that Sabberworm\CSS\CSSList\Document::splice() is not defined.

However, the Sabberworm\CSS\CSSList\Document class extends Sabberworm\CSS\CSSList\CSSBlockList: https://plugins.trac.www.ads-software.com/browser/amp/tags/1.0.1/vendor/sabberworm/php-css-parser/lib/Sabberworm/CSS/CSSList/Document.php#L8

And Sabberworm\CSS\CSSList\CSSBlockList extends Sabberworm\CSS\CSSList\CSSList: https://plugins.trac.www.ads-software.com/browser/amp/tags/1.0.1/vendor/sabberworm/php-css-parser/lib/Sabberworm/CSS/CSSList/CSSBlockList.php#L16

And Sabberworm\CSS\CSSList\CSSList defines the splice method: https://plugins.trac.www.ads-software.com/browser/amp/tags/1.0.1/vendor/sabberworm/php-css-parser/lib/Sabberworm/CSS/CSSList/CSSList.php#L61

So I don’t know why the plugin would error for this not being defined on your installs.

We installed the plugin via wordpress. IF you need admin access to troubleshoot let us know. We have a test site setup

OK, please ping me on WordPress Slack with the login details.

@mexl Do you have the Mail Poet plugin installed per chance?

The issue appears to be that another plugin has a conflicting version of PHP-CSS-Parser, one which does not have the splice method.

Here is a pull request and build of the plugin to try which includes detection for PHP-CSS-Parser library conflicts: https://github.com/ampproject/amp-wp/pull/1743#issuecomment-447174483

Please test.

The issue is PHP-CSS-Parser when combined with MailPoet (in our environment). PR fixed our issue and performs stable in testing. Thanks for the help @westonruter

@westonruter Thank you, yes, all our sites use Mailpoet.
All the best!