Hoi Henning, > 3) The following is printed out for many, many (every?) event > CompIbuNtpDump::BtaMcAssoc.cc(410):BtaMcAssoc::checkPdtHypo: returns 0 because pdtEntry > or candidate is null. Please check that you have > valid candidates before calling this method. > o original candidate pntr: 0x13b9b740 > o original candidate pdtEntry pntr: 0xff4d0d8 > o matched candidate pntr: (nil) > o matched candidate pdtEntry pntr: (nil) Is this for beam-background neutrals? No. I just checked in one of your trees that you MUCH more unmatched neutrals than messages in the corresponding logfile. And there are MUCH less unmatched tracks than messages. It is not per event, in the logfile I checked there are 296 messages for 978 events read in. Cheers, --U.