The trunk50-64-NNNNN image is a Squeak trunk 5.0 image at update level NNNNN that has been converted to 64-bits. Use a 64-bit Spur VM to use this image. See VMs under ../VM. As of 11 March 2016 the 64-bit Spur format changed; the tag pattern for SmallFloat64 instances changed from 3 to 4, to solve a clash with the 32-bit image. Consequently: - older VMs will not run newer images - newer VMs will not run older images - older 64-bit Spur images should be discarded. Eliot Miranda March 2016