404

I still have problems with the 404. My page is in German and when I switch to English I get a 404. I did the update, deleted strings as well as the cache and minification. After that I optimized the tables and much more, always the same error. I deleted the plugin and reloaded it again. All helps nothing and still get 404. What else can I do to make Polylang work. I am actually very excited about the plugin when it works, actually works very well.

browser 1: Detect browser language activated
rewrite 1: Remove /language/ in pretty permalinks
hide_default 1: Hide URL language information for default language
force_lang 1: The language is set from the directory name in pretty permalinks
redirect_lang 1: The front page URL contains the language code instead of the page name or page id
media_support 0: The media are not translated
sync
0: taxonomies
1: post_meta
2: comment_status
3: ping_status
4: sticky_posts
5: post_date
6: post_format
7: post_parent
8: _wp_page_template
9: menu_order
10: _thumbnail_id
post_types post, page, wp_block, client, layout, offer, portfolio, slide, template, testimonial
taxonomies category, post_tag, client-types, offer-types, portfolio-types, slide-types, testimonial-types
version 3.4.1
default_lang de
menu: main-menu de => 7 | en => 716
menu: secondary-menu de => 0 | en => 0
menu: lang-menu de => 0 | en => 0
menu: social-menu de => 0 | en => 0
menu: social-menu-bottom de => 0 | en => 0
menu: skip-links-menu de => 0 | en => 0
previous_version 3.4

The page I need help with: [log in to see the link]