Database connection not found

Hi I have a customer management system working on Prod for a couple of years working without a problem, I have some apps that are public and not going through the security module.
All this apps are not working now (they were before) I am receiving the error Database nor found
If I sine in using the security module everything works ok which means that the connection is there an working.
Not sure when this started as I did not noticed before but some of my customers started calling when trying to setup an appointment
This apps are different one is a grid the other is a form and I even have one blank app and all of them with the same problem

Any idea how to fix this?

To fix this i had to redeploy the full project using a zip file, I was deploying with FTP directly to the server and the problem persist, now that I learned this all my project is working fine with no errors