java.lang.StringIndexOutOfBoundsException in inbound fileadapter XI2.0

When I want to presess a message in my inbound fileadapter (XI 2.0), I get the following error :

Exception in XML Renderer (format problem?)

java.lang.Exception: ERROR converting document line no. 1 :

java.lang.StringIndexOutOfBoundsException: String index out of range: 369

What I think, is that the record structure does not match the structure as expected.

How can I find out what is wrong (like the 369 position in the errormessage, what does that tell me ?)

below the (partial) adapterconfiguration.

xml.processFieldNames=fromConfiguration

xml.fieldNames=BSYSTEM,INTERFACEID,LOCSOC,LONLOT,LONPIE,LONLIG,LOCJOU,LODAAC,LODMMC,LODJJC,LOTPIE,LOCDEV,LOCOUR,LOLECR,LODAAP,LODMMP,LODJJP,LODAAV,LODMMV,LODJJV,LOTYPC,LONCPT,LONEXT,LONTFF,LOMTDV,LOSECR,LOSTAP,LOSTAT,LOQTES,LOTCEN,LONCEN,LOCTVA,LOTNTE,LOCNTE,LOVTA1,LOTDS1,LOCDS1,LOVTA2,LOTDS2,LOCDS2,LOVTCR,LOCNPI,LOCRLT,LOCNLT,LOMREG,LODAAE,LODMME,LODJJE,LOFLG3,LOCEXT,LOVTLT,LOLNPI,LOLRLT,LOLNLT,LOLEXT,LONLGT,LONGRP,LOMJ00,LOMJ01,LOMJ02,LOMJ03,LOMJ04,LOMJ05,LOMJ06,LOMJ07,LOMJ08,LOMJ09,LOMJ10,LOMJ11,LOMJ12,LOMJ13,LDMJ14,LOMJ15,LOMJ16,LOMJ17,LOMJ18,LOMJ19,LOMJ20,LOANUL,LOTCCP,LONCCP,LOMJ21,LOMJ22,LOMJ23,LOMJ24,LOMJ25,LOMJ26,LOMJ27,LORDAS,LOMJ28,LOMJ29,LOMJ70,LOMJ71,LOMJ72,LOMJ73,LOMJ74,LOMJ75,LOSERV,LOSTC1,LOSTC2,LOSTC3,LOSTC4,LOSTC5,LOSTC6,LOFIL2

xml.fieldFixedLengths=15,3,2,4,9,5,2,2,2,2,3,3,15,30,2,2,2,2,2,2,1,8,10,15,15,1,5,16,15,1,8,1,1,8,1,1,8,1,1,8,1,9,9,9,1,2,2,2,1,1,1,9,9,9,1,3,9,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,8,3,3,3,1,1,1,1,2,1,1,1,1,1,1,1,1,3,2,3,4,6,8,10,10

xml.lastFieldsOptional=yes