Invalid target configuration error when connecting to database

Hello @Comet.
I had the same problem because as Brian already stated, most host providers deny any access from outside. The Wappler devs tried to overcome this problem by first sending the database parameters to the server and testing the connection from there. Problem is, even this package that is sent from Wappler gets blocked by certain providers, so the script on the server doesn't get the parameters for testing. The team already looks into that and as I know them, they fix this soon:

Please try to change the parameters in /dmxConnect/modules/Connections/yourConnection.php, then upload your page to the remote server and check out if it connects to your database. This solution was brought to me by Dave: