Feature request: provide more information when error = "not well-formed (invalid token): line 604, column 53"

[JozefAerts]

When a define.xml is involved, one may get the error:
"error":"An unknown exception has occurred"
"message":"not well-formed (invalid token): line 604, column 53"

For me (Define-XML expert ;-)) it is clear that this means that the define.xml is not "well formed", and that the problem probably occurs at line 640 in the define.xml, but for the non-export, it may come as a mistery.
Therefore I propose to adapt the message into:
"define.xml: not well-formed (invalid token): line 604, column 53" or something similar ...