The contact form isn't working, it gives me 2 warnings : JUser: _ load Unable to load user with ID ..
and "You must provide at least one recipient email address"

For the first error i found a fix, but wanted to ask if adding a new superuser and change its id to the missing one, isn't a security risk?

And for the second error, no clue. It sends a copy of the message to the sender, but none of the admins get anything sent from the contact form.
I think this could be a template issue? I installed the copy I was working locally, before I had another site working on my host and the contact form worked fine - I deleted the previous site and the database, so this migration was clean.

Thanks in advance for any help or suggestions!

For the first error i found a fix, but wanted to ask if adding a new superuser and change its id to the missing one, isn't a security risk?

Not at all, since nobody knows his login name and his id (which is not the default one) then there is no risk, unless the password is 123456.

It sends a copy of the message to the sender, but none of the admins get anything sent from the contact form.

Did you change the linked user in the contact form's parameters after deleting the admin?

Krikor wrote: Did you change the linked user in the contact form's parameters after deleting the admin?

That may be the issue, but the contact form is not a module, or a plugin, where can I access those parameters?

You need to go to Components -> Contacts -> Contacts.