Hi,
my colleagues and me have the same problem. It appears when we select the parts of the block we want to edit.
Sometimes ACADM (6) crashes directly to the desktop, sometimes we get a fatal error line ('Unhandled Access Violation Reading .......(numbers change from block to block) Exception at 36021373h').
After restarting ACADM we sometimes are able to use refedit on the block, sometimes not.
It's about 50% of all refedits, that a crash happens.
We'd be very glad about any help.