Indeed, it's ok, thank you very much Ciaran

Thank you

The issue appears to be related to your YT Shortcodes plugin. Disabling this plugin appears to resolve the issue.

Ciaran

Thank you, message sent to info@joomla51.com

Hello

It is hard for us to say what may be causing this. It is an issue that has not been presented before. May I suggest sending temporary administration access to your Joomla installation to info@joomla51.com and we will examine this issue further. For our reference please paste a link to this post in your email.

Ciaran

Thank you very much Ciaran :-)
I installed the new version of the template, still the same problem.
I bypassed the problem: system / configuration / system / debugging system yes
then
media file / cms / css / debug.css
line 90 I added display: none;

div # system-debug {
margin: 5px;
display: none;
}

Now the menu and the slideshow appear ;-)
??

Best regards

Hello

May I suggest sending temporary administration access to your Joomla installation to info@joomla51.com and we will examine this issue further. For our reference please paste a link to this post in your email.

Ciaran