export album to library cancels with The library has not been exported to “(null)” because the operation was canceled.

It drives me bonkers! This msg (4 x already with different projexts!) does not make any sense to me! all i want to do is to export a project as a new library! what am i doing wrong? the project contains more than 17800 images!

The library has not been exported to “(null)” because the operation was canceled. (=why, by what? more information would be appreciated!)

Any ideas/help? Maybe there is a blockage in my way of thinking? 😟

Confiburation: Aperture 3.5.1, MAC OS X Mavericks (10.9.2) on an

imac i7qc, 27", 2093 GHz, 8 GB 1333 MHz DDR3,