Tony, The browser is failing when it encounters data that is not KpixDataRecord (as best I can tell). It will throw this error message for the first few events and then when it encounters a data record it works fine. Then it eventually fails again when it encounters another non-data record. We are using jas 3.0.3 I'm including a few screenshots. Also, would it be possible for the reader to have a cache of events. It would be nice to rewind if you're clicking through events and accidentally pass something interesting. -Dylan ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the KPIX-BEAMTEST-SOFTWARE list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=KPIX-BEAMTEST-SOFTWARE&A=1