I've been able to replicate this pretty reliably. It has a very specific set of circumstances to trigger it, so bear with me here.
Behavior:
Networked server crashes on Macro Delete.
Variables:
-The macro needs to be merged from a different show file. Macros created in the current show file seem to be able to be deleted no problem.
-When I try to delete the Macro it needs to be from the client console (can be either a client or failover/backup server).
-this last step isn't 100% confirmed, but I theorize that the macro needs to also refer to fixtures that do not exist in the current showfile.
Cheers! let me know if you need any additional info trying to replicate this one...
-Elton