Url ends in 404 error (various components)

another step:

when I disable the automatic switch language in the language filter plugin it works.
sofar almost every menu is working now, exept of one...I can do what ever...still 404

Hello

what type of menu item is this ?

it was a joomla article menu item and I tried a flexicontent article item now but still 404...I found something that is also strange I wanted to filter the categories in the menu item selection but had no categries to choose from...please see the attached screenshot

another step:

I used the same menuitem but changed the article and it works...

ok, I think I found the problem with the last 404 error... we have a tab plugin that causes the error.

when I delete the tab code it works

the guys from Jutab fixed the problem and everything works properly again. Thank you for your assistance and your super support!