FlowJo has determined that the data file is an FCS file, but encountered an error while trying to read the header information. There is a certain set of keywords that are absolutely needed by FlowJo (and are part of the standard FCS3.0 keyword set). FlowJo does not require any keywords not specified by the FCS standard.

You will not be able to read this file. If you feel that the FCS file follows the standard FCS format and is uncorrupted, please see the page about contacting the FlowJo administrators.