The error appears to be quite clear: "IO Error: The Network Adapter could not establish the connection". Probably you need to seek assistance of a sys admin as there seems to be a bad network connection between the Mendix application and the database server.
We are experiencing this same issue in Mendix 3.3.2. We are running on an ORACLE database, and these errors keep re-occurring.
It has happened twice now today. We've been looking at Database, Network, Application Server and they all are running smoothly without any issues.
Any idea as to what might cause this?
The error seems to sort it self out as the users can continue processing after 5minutes or so without any intervention from us (IT). But when the error occurs, users are unable to do anything in the system until the error stops in the console.
I Sometimes get this error during development. In my case the db service seems to crash causing the modeller to loose connection with the db.