Armadillo on private Ubuntu LAMP - Can't save the settings

I developed on MAMP a website using RW+Foundation+Armadillo; everything works fine.
Now, at the end of the work, I have to publish the site on my customer’s private dedicated Ubuntu 16.04 LAMP.
I installed and setup Apache2+Mysql and publish the site. Everything works fine but in Armadillo settings I can’t save the settings; I’ve got an error as “An error occured when trying to save”.
No info in apache error log. I spent more than 3 days to search a solution, without success.
I wrote to Armadillo support 5 days ago, but I haven’t a response yet, and at the end of this week I have to release the new site; I’m stuck :unamused:.
I have total control of the Ubuntu server, so I can do everything, but unfortunately I can’t understand what’s wrong.
Any suggestion will be appreciated.

Do you have a php log file? Maybe that’s different from the apache log file?

Here you can find the apache log file
Apache error log file

and here you can find the error generated when the settings page is shown.
Error on settings page shown

On the server I edit the /etc/hosts adding:

So now I can test everything as the site will be publish.
Can this configuration make problems with ajax used by armadillo?

@pietrob71 Based on the error log when saving settings, the problem is with the tags/categories - do you have any specified for any posts?

I have no specified tags and categories, for now. Removing all the posts, with an sql on the armadillo_posts table, the problem persists.

What I might suggest is to create a post, assign it a tag (or category), then save that post as a draft. Then go into the Settings tab and try saving again - does the issue still occur at that point?

After delete all posts and blog, also creating a new post and save it, I’m unable to save.

Take a look at this screencast

@pietrob71 I’ve just sent you a reply via our support system so I can troubleshoot further.