did you lose network connection at some point whilst archiCAD was running?
have you closed archiCAD and tried again with your network fully running?
it won't affect the archiCAD file in any way in the long term - archiCAD still remembers the objects even if they aren't loaded. it
will affect your current session with archiCAD as the library parts won't show on screen or print.
a few minutes with library manager should sort it out if the above doesn't work.
~/archiben
b e n f r o s t
b f [a t ] p l a n b a r c h i t e c t u r e [d o t] n z
archicad | sketchup! | coffeecup