Maximenu CK Mobile Plugin Not Saving

Just installed the Maximenu CK Mobile plugin. None of the Save / Save and Close / Close buttons are working, so I'm unable to save any styles options.

The plugin appears to be trying to load insecure content, which is being blocked:
Blocked loading mixed active content " update.joomlack.fr/plg_maximenuckmobile_...teck&_=1570390885154 "

And on the Styles options tab, the Preview button shows constantly rotating spinner.

Other plugins / modules / content are all saving correctly, it just appears to be this one.

Any ideas?

Hi
can you please confirm that you have the module Maximenu CK installed ? and also the native "com_ajax" activated
this is needed

CEd

The module is installed and the menu works fine. The menu parameters plugin is also working OK. The mobile plugin is working also, switching to the mobile menu. It's just the backend of the plugin that's the problem. I can't change any of the settings (styling etc) as I can't save them.

com_ajax is active by default isn't it? Doesn't need activation as such. It's a standard Joomla installation, com_ajax is there, so should be working.

Thanks

Also, I have done all the 'normal' things - re-installing, clearing caches, and tried using a different browser with the same result.

ok then please send me an admin access by email
www.joomlack.fr/en/contact

the error is :

An error has occurred.

404 Component not found.

>> the com_ajax is missing, you must check that (I can not as I only have limited admin rights)