wpsnoop Fatal error: Cannot redeclare plugin_mce_css()

If you are dealing with a WordPress issue where a PHP Function plugin_mce_css() was already declared it is most likely due to a plugin/theme conflict.

wpsnoop scanned and analyzed over 100,000 WordPress plugins and themes to find and locate potential conflicts including functions that share the same name.

This page has information on the 11 places where that function is declared and used in WordPress plugins and themes.

Note: Our database currently only taps into the free themes and plugins available in the publicly available WordPress plugins and themes, if your site uses paid plugins, themes or custom code there may be additional conflicts.

Our database has uncovered 11 different instances of potential conflicts where different plugins or themes share the function name.

Examples of this error include:

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/ps-tools/ps-tools.php:31)

This file is part of the WordPress plugin Photoshop Tools and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/mce-accessible-language-change/mce_accessible_language-change.php:32)

This file is part of the WordPress plugin MCE Accessible Language Change and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/blind-friendly-admin/blindfriendly-admin.php:619)

This file is part of the WordPress plugin Blindfriendly Admin and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/tinymce-editor-font-fix/webist-tinymce.php:12)

This file is part of the WordPress plugin TinyMCE editor Font FIX and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/bible-post/biblepost.php:421)

This file is part of the WordPress plugin Bible Post and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/admin-font-editor/admin-font-editor.php:288)

This file is part of the WordPress plugin Admin Font Editor and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/accessibility-abbreviation/accessibility-abbreviation.php:13)

This file is part of the WordPress plugin Accessibility Abbreviation and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/accessibility-language/accessibility-language.php:13)

This file is part of the WordPress plugin Accessibility Language and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/wp-editor-tweaks/wp-editor-tweaks.php:28)

This file is part of the WordPress plugin WP Editor Tweaks and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/bootstrap-mce-css/bootstrap-mce-css.php:19)

This file is part of the WordPress plugin Bootstrap MCE CSS and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare plugin_mce_css() (previously declared in wp-content/plugins/thirteen-colors/thirteen-colors.php:189)

This file is part of the WordPress plugin Thirteen Colors and could be interacting with another theme or plugin and causing a fatal error.

The error occurs because two (or more) plugins that you are using are both trying to declare a function with the same name.