Bluish suite App

Fatal error: Uncaught TypeError: implode(): Argument #2 ($array) must be of type ?array, string given in /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/inc/frontend.php:1695 Stack trace: #0 /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/inc/frontend.php(1695): implode(Array, ',') #1 /customers/6/2/6/halstrick.de/httpd.www/wp-includes/class-wp-hook.php(326): oxy_adjacent_post_where('WHERE p.post_da...') #2 /customers/6/2/6/halstrick.de/httpd.www/wp-includes/plugin.php(205): WP_Hook->apply_filters('WHERE p.post_da...', Array) #3 /customers/6/2/6/halstrick.de/httpd.www/wp-includes/link-template.php(1967): apply_filters('get_previous_po...', 'WHERE p.post_da...', false, '', 'category', Object(WP_Post)) #4 /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/partials/shortcodes/headings/heading-portfolio.php(12): get_adjacent_post(false, '', true) #5 /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/inc/options/shortcodes/shortcodes.php(182): include('/customers/6/2/...') #6 /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/inc/frontend.php(1441): oxy_section_heading(Array, 'Bluish suite Ap...') #7 /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/inc/frontend.php(1527): oxy_call_shortcode_with_meta('oxy_section_hea...', Array, 'Bluish suite Ap...', Array, Array) #8 /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/single-oxy_portfolio_image.php(16): oxy_page_header(273, Array) #9 /customers/6/2/6/halstrick.de/httpd.www/wp-includes/template-loader.php(106): include('/customers/6/2/...') #10 /customers/6/2/6/halstrick.de/httpd.www/wp-blog-header.php(19): require_once('/customers/6/2/...') #11 /customers/6/2/6/halstrick.de/httpd.www/index.php(17): require('/customers/6/2/...') #12 {main} thrown in /customers/6/2/6/halstrick.de/httpd.www/wp-content/themes/omega/inc/frontend.php on line 1695