This very likely indicates disk corruption outside of bzr. If you have a backup, or you have pushed this branch elsewhere, I suggest you restore from that. Otherwise, try removing all the files called 'ac5cb60a3aa533a7ded9fc433bcac5c1*' from under .bzr/, then run bzr pack, and that might fix the problem.
Hi,
This very likely indicates disk corruption outside of bzr. If you have a backup, or you have pushed this branch elsewhere, I suggest you restore from that. Otherwise, try removing all the files called 'ac5cb60a3aa533 a7ded9fc433bcac 5c1*' from under .bzr/, then run bzr pack, and that might fix the problem.