A 718 error generally means there's something wrong with the XML file you're importing. Perhaps it's either not valid XML ( bad characters etc ) or not properly formed XML ( all the right closing tags ). If you're able to share I'm happy to have a look at it offline for you.
There is not an xml file error or xslt error as it works on many of the other FMPA11 product / 11 server and FMPA 13. I reported this issue to FileMaker support and they confirmed it is a bug. You can view the xml and xslt on the filemaker support site.
I am having the same issue on xml import script. Was working great on filemaker server 12 but not on 13. I am also getting error 2035. Any solution yet?
I believe this is a known bug, I'll try to find the links to the reports when I've finished traveling. From memory they are on the FileMaker forums under 'Report an Issue'.
This is costing us money as we're having to retain hosted FMS12 servers for those customers using XML imports.
Found the link: http://forums.filemaker.com/posts/5ff55702d0