Title: PHP 8 Issues
Last modified: January 18, 2022

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# PHP 8 Issues

 *  Resolved [Howdy_McGee](https://wordpress.org/support/users/howdy_mcgee/)
 * (@howdy_mcgee)
 * [4 years, 4 months ago](https://wordpress.org/support/topic/php-8-issues-6/)
 * Hello,
 * I’m trying to use this plugin via PHP 8 but keep running in the same error:
 * > PHP Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($
   > callback) must be a valid callback, non-static method change_case::register_button()
   > cannot be called statically
 * I think the issue may be the following filter hook:
 * add_filter( ‘mce_buttons’, array( __CLASS__, ‘register_button’ ) );
 * The `register_button()` defaults to being public but not static since it’s missing
   the static keyword. If the static keyword is added, this should fix the PHP 8
   issue.

The topic ‘PHP 8 Issues’ is closed to new replies.

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 * 0 replies
 * 1 participant
 * Last reply from: [Howdy_McGee](https://wordpress.org/support/users/howdy_mcgee/)
 * Last activity: [4 years, 4 months ago](https://wordpress.org/support/topic/php-8-issues-6/)
 * Status: resolved