Open Source Document Management System | OpenKM

When I preview a pdf ducument, an error occurs "Dictionary key must be a name object"; sometimes the pdf can display normally, but sometimes not.
I don't know why and I am looking forward for your help.

Seems a pdf2swf conversion problem, I suggest take a look at official swftools website and looking for information about all command parameters, probably some change on default pdf2swf parameter will solve it. Try the command with conflictive pdf from command line.