Title: PHP Error: Leafo Compatability
Last modified: April 30, 2019

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# PHP Error: Leafo Compatability

 *  Resolved [bpfergu](https://wordpress.org/support/users/bpfergu/)
 * (@bpfergu)
 * [7 years, 1 month ago](https://wordpress.org/support/topic/php-error-leafo-compatability/)
 * Hello,
 * After updating my PHP and maxbutton plugin, I am receiving the following error:
 * Declaration of Leafo\ScssPhp\Formatter\Compressed::format(Leafo\ScssPhp\Formatter\
   OutputBlock $block) should be compatible with Leafo\ScssPhp\Formatter::format(
   Leafo\ScssPhp\Formatter\OutputBlock $block, ?Leafo\ScssPhp\SourceMap\SourceMapGenerator
   $sourceMapGenerator = NULL)
 * This is only happening on one of my sites, however. On my other sites that are
   running the same PHP version and version of maxbuttons, everything seems to be
   fine.
 * Any idea what is causing this?

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Author [AlanP57](https://wordpress.org/support/users/alanp57/)
 * (@alanp57)
 * [7 years, 1 month ago](https://wordpress.org/support/topic/php-error-leafo-compatability/#post-11492711)
 * I’m not sure. What PHP versions are involved.
 *  Plugin Author [Bas Schuiling](https://wordpress.org/support/users/basszje/)
 * (@basszje)
 * [7 years, 1 month ago](https://wordpress.org/support/topic/php-error-leafo-compatability/#post-11516366)
 * This cause of this is another plugin you have in use that doesn’t check if this
   library is already loaded ( as MaxButtons does ). To solve, please check which
   plugin that might be, and request they check for this first.

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘PHP Error: Leafo Compatability’ is closed to new replies.

 * ![](https://ps.w.org/maxbuttons/assets/icon-128x128.png?rev=1378636)
 * [MaxButtons - Create buttons](https://wordpress.org/plugins/maxbuttons/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/maxbuttons/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/maxbuttons/)
 * [Active Topics](https://wordpress.org/support/plugin/maxbuttons/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/maxbuttons/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/maxbuttons/reviews/)

## Tags

 * [php-error](https://wordpress.org/support/topic-tag/php-error/)

 * 2 replies
 * 3 participants
 * Last reply from: [Bas Schuiling](https://wordpress.org/support/users/basszje/)
 * Last activity: [7 years, 1 month ago](https://wordpress.org/support/topic/php-error-leafo-compatability/#post-11516366)
 * Status: resolved