Here in Jira you can find a lot of tickets with error like :

Template import fails: Invalid parameter "/14/key": must contain at least one low-level discovery macro.

Yes, those details what field name is affected help a little. But it's not possible to figure out where is the object!
I guess that the number 14 (variable) in current example is indicating something in the order, but it does not help.

For example I had a file export with 5 templates, bigger ones, and it was really pain to find out the line which is failing.

So, the message should be improved to indicate someway how to identify the line or object. It could be line number, if object's UUID or name.