Problem with the main navigation in Internet Explorer / Microsoft Edge

Hello Forum User´s,

Here is a website:
The Problem is that the main navigation is working in Chrome & Firefox but not correctly in Edge or Internet Explorer. The submenu is not unfolding.
I guessed it had something to do with the display proberty of the ul class “dropdown-menu” but thats seems not the case.

Anyone an idea?



The hamburger menu isnt working in Firefox and FirefoxDeveloperEdition (Mac and PC).

Works in Chrome (Mac and PC), Brave and Safari though. (which I think all use the same web engine)

There are no errors in the Console either.

Is this Bootstrap? Have you tried not doing any minimization to see if it works?

Hi owel,

thx for you reply.
Its not Bootstrap.
Sorry I have to ask but what do you mean exactly with “minimiaztion”?


Why are you supporting Internet Explorer still? I understand Microsoft Edge but as far as I remember Microsoft disabled support for Internet Explorer. Is this a legacy project for a company or something personal?