This looks like a rather strong effect of a problem I noticed yesterday. To solve it please edit php/class/rpr_taxonomies and insert some code around line 62 just after $this->taxonomies = get_option('rpr_taxonomies', array());
and before // register taxonomies:
// Restore taxonomies if active but deleted:
if( !isset($this->taxonomies['rpr_ingredient']) ){
$this->taxonomies = $this->add_taxonomy_to_array($this->taxonomies, 'rpr_ingredient', __( 'Ingredients', $this->pluginName ), __( 'Ingredient', $this->pluginName ), true);
}
if( $rpr_option['taxonomies']['rpr_category'] == '1' && !isset($this->taxonomies['rpr_category']) ){
$this->taxonomies = $this->add_taxonomy_to_array($this->taxonomies, 'rpr_category', __( 'RPR Categories', $this->pluginName ), __( 'RPR Category', $this->pluginName ), true);
}
if( $rpr_option['taxonomies']['rpr_tag'] == '1' && !isset($this->taxonomies['rpr_tag']) ){
$this->taxonomies = $this->add_taxonomy_to_array($this->taxonomies, 'rpr_tag', __( 'RPR Tags', $this->pluginName ), __( 'RPR Tag', $this->pluginName ), false);
}
if( $rpr_option['taxonomies']['rpr_course'] == '1' && !isset($this->taxonomies['rpr_course']) ){
$this->taxonomies = $this->add_taxonomy_to_array($this->taxonomies, 'rpr_course', __( 'Courses', $this->pluginName ), __( 'Course', $this->pluginName ), true);
}
if( $rpr_option['taxonomies']['rpr_cuisine'] == '1' && !isset($this->taxonomies['rpr_cuisine']) ){
$this->taxonomies = $this->add_taxonomy_to_array($this->taxonomies, 'rpr_cuisine', __( 'Cuisines', $this->pluginName ), __( 'Cuisine', $this->pluginName ), true);
}
if( $rpr_option['taxonomies']['rpr_season'] == '1' && !isset($this->taxonomies['rpr_season']) ){
$this->taxonomies = $this->add_taxonomy_to_array($this->taxonomies, 'rpr_season', __( 'Seasons', $this->pluginName ), __( 'Season', $this->pluginName ));
}
if( $rpr_option['taxonomies']['rpr_difficulty'] == '1' && !isset($this->taxonomies['rpr_difficulty']) ){
$this->taxonomies = $this->add_taxonomy_to_array($this->taxonomies, 'rpr_difficulty', __( 'Difficulties', $this->pluginName ), __( 'Difficulty', $this->pluginName ));
}
This should do the trick.
What I did not test yet is what happens to custom taxonomies. Will look into that later today.