[NSFW] Keep getting errors and “page not found” !?

The following is found in the error.log:

[30-Jun-2020 15:09:17 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/bring2mi/public_html/wp-content/plugins/advanced-sidebar-menu-pro/src/Nav_Menu/Objects.php on line 254
[30-Jun-2020 15:09:17 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/bring2mi/public_html/wp-content/plugins/advanced-sidebar-menu-pro/src/Nav_Menu/Objects.php on line 192
[30-Jun-2020 16:02:40 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/bring2mi/public_html/wp-content/plugins/advanced-sidebar-menu-pro/src/Nav_Menu/Objects.php on line 254
[30-Jun-2020 16:02:40 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/bring2mi/public_html/wp-content/plugins/advanced-sidebar-menu-pro/src/Nav_Menu/Objects.php on line 192
[30-Jun-2020 16:15:34 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/bring2mi/public_html/wp-content/plugins/advanced-sidebar-menu-pro/src/Nav_Menu/Objects.php on line 254
[30-Jun-2020 16:15:34 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/bring2mi/public_html/wp-content/plugins/advanced-sidebar-menu-pro/src/Nav_Menu/Objects.php on line 192

I tried to enable debug and error message display, but then the menu would not show at all, just the error messages on the webpage.

View the page.

https://www.bring2mind.se/our-work/armoured-protected-tracked-and-wheeled-vehicle-systems/armoured-protected-tracked-and-wheeled-vehicle-system/

The left sidebar menu has been configured in a widget, which is added to the page. It looks nice, but gives me errors and sometimes “page not found”.

Can You help me ?

Rgds/Gunnar

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