Qualys scan report can not be import into Fortiweb scanner file

[Joy]

Hello All, I try to import Web vulnerability scan from qualys into fortiweb with a XML file, but it fails.It always shown error messages "Failed to process the upload file".  I have tried two different fortiweb os 5.54,build0739, 160704 and 5.53,build0730,160426, but got the same result. Anyone has same experiences, other limitations or requirements on Fortiweb or Qualys?  I also looking for some docs about fortiweb, but no mention of the relevant. Thanks. Joy Liu