latin1sequences in the XML log file (from a conversion from latin to UTF-8 long time ago), and that makes logfile parsing fail. To sanitize this, I use the following filter:
iconv -c -f UTF-8 -t UTF-8
This way, obnoxious sequences are dropped and processing can go on. (or, at least, could go on if it was not failing just a little later with a Null pointer exception...).