Bad update of what? This is what I get: 98: [PEAPI]PEAPI.CustomModifier If I do a cvs update -Pd . and rebuild will that do it? -----Original Message----- That's probably the result of a bad update. Anyway, if you want to know what's missing, run 'monodis --typeref ilasm.exe | grep ^98' and you'll get the type name. Update that assembly and everything should work.