Hello,
We've run into an issue a couple times before and couldn't solve it and we worked around it. It just came up for me now again and I tracked down the cause, finally.
When setting up a new Destination in the Deployment Tool and trying to test the connection, I get the following error: Could not connect. Unexpected character encountered while parsing value: <. Path '', line 1, position 1.
It turns out that it has to do with the password. If there is a colon (:) in it, then this issue occurs. Possibly other characters are problems, but at least the : is a problem. This should be reproducable from any version that has the deployment tool.
It's not any hurry for me at all since I know how to work around it now, so I'm just reporting to help improve the platform.
Thanks,
Scott