Octavian Iosif

Same problem here. WordPress changed the class definition for Walker, it now reads

public function walk( $elements, $max_depth, …$args ) {

before it was

public function walk( $elements, $max_depth, $args ) {

Since the Polylang PLL_Walker class extends that, you get an error. Should be a simple fix.

The latest version fixed it, as did the fix on Github, thank you for the quick fix!