Improve exception when automation chain design is broken

I create the following chain name "Test" attached to an user action:

• Fetch > Query (SELECT * FROM Document)
• Conversion > Render Document (create an empty template)
• User Interface > Download file

• I deploy this chain
• I Click on the button

Problem:

• Error returned into UI "Test chain unknown"
• No exception into server log

Waiting resolution:

• Having a real stacktrace error that helps me to find that Conversion will returned a bloblist and Download File accept only Blob.