Thanks for the advice, plugin CF7 Views causes the problem.
Theme Salient
other Plugins: Better Search Replace, CF7 Views, Classic Editor, Classic Widgets, Contact Form CFDB7,
Envato Market, EventON, Flamingo, Members, phpinfo WP, Polylang, Salient Core, Salient Custom Branding, Salient Demo Importer, Salient Home Slider, Salient Nectar Slider,
Salient Portfolio, Salient Shortcodes, Salient Social, Salient Widgets, Salient WPBakery Page Builder, Ultimate Member, UpdraftPlus – Backup/Restore, Wordfence Assistant, Wordfence Security, WP Activity Log, WP Armour – Honeypot Anti Spam, WP Media folder, WP Media folder Gallery Addon, WP-Optimize – Clean, Compress, Cache, wpForo, Yoast SEO
Hello, thank you for your answer. You can find the form at https://www.jdost.at/en/membership/
Kind regards from Vienna,
Michael
