Hi @phands I hope you don’t mind me splitting your comment to a new post - I wanted to make sure that your question didn’t get lost. 

It can be really tricky connecting to databases, because there are a lot of different security settings that can get in the way. Often that means that we don’t get very helpful error codes from services. I Googled the error code 225 for AWS RDS and found: Command failed. There were errors thrown by either the CLI or by the service the request was made to. That doesn’t really get us any further as to why the command failed. 

Could I ask at what point you’re seeing the error? Is it when you’re connecting your AWS RDS account in the Zap, when you’re testing a step, or have you been able to turn on the Zap and it’s now running into errors? If you could include a screenshot of where the error is happening that will help us to better understand where in the process things are running into trouble. Thanks!

Hi, and thanks for taking the time to reply.

The error occurs in the connection step.  I use a known good user/password pair, not an SSH setup.

I’m in the “Allow Zapier to access your MySQL Account?” screen.  I fill in the details - which I won’t reveal here - and then click “Yes, Continue”, and immediately get the 255 error.  I have tried the RDS-supplied URL, the EC2 instance URL and the IP V4 address of the db server, all with the same outcome. Attached are redacted screenshots….