The following works or does not work while editing in the frontend.

There are no further pop-ups, so no photos, no links etc. can be entered.

What can / must I do to make it work?

Installed is Joomla 3.8.6, K2 Version 2.7.1, PHP 5.6.34
Sj_expnews is installed as template.

We have installed K2 V. 2.7.1 because the version 2.8 causes problems.

I found out by now that K2 seems to have problems with various templates that work with frameworks.

Now I have a Template Plain with YT Framework and one with Helix 3 Framwork installed.

Templates that work with the YT Framework: no chance
Template working with Helix 3: no chance

No matter which PHP version I also activate, with no installation the editing of the K2 articles in the frontend works.

Does any of you know a solution?

Hello,

Are you seeing any JS errors in your browser's developer tools' console tab?

Yes

TypeError: $(...).tooltip is not a function

this is the error message


I always get to see the following

Are you using a custom backend or frontend editing template?
Can you check if multiple instances of jQuery are being loaded?