Hello Stefan, I modified the uuid.mal file in the lib directory and that all works great for a small sample test from mclient. Thanks! Now I have run into a problem where the server crashes when I try to insert into one of the tables, though inserts in other tables work fine. I do not think this problem has anything with UUIDS as the table I am inserting into does not use UUIDS and I can do inserts into tables that have uuid columns. This insert that causes the crash worked fine on the last version of our schema that did not use UUIDs. I have a small database from msqldump and an insert statement that causes the server to crash consistently. However, I do not see any way to add attachments to a bug report on the tracker. Is there a way to do this? Is there any other information I can collect that would be useful in a bug report? Here is the monetdb log which shows a sigsegv. Doug 2015-10-06 16:02:19 MSG quantbox[3433]: # MonetDB 5 server v11.21.5 "Jul2015" 2015-10-06 16:02:19 MSG quantbox[3433]: # Serving database 'quantbox', using 4 threads 2015-10-06 16:02:19 MSG quantbox[3433]: # Compiled for x86_64-pc-linux-gnu/64bit with 64bit OIDs and 128bit integers dynamically linked 2015-10-06 16:02:19 MSG quantbox[3433]: # Found 1.907 GiB available main-memory. 2015-10-06 16:02:19 MSG quantbox[3433]: # Copyright (c) 1993-July 2008 CWI. 2015-10-06 16:02:19 MSG quantbox[3433]: # Copyright (c) August 2008-2015 MonetDB B.V., all rights reserved 2015-10-06 16:02:19 MSG quantbox[3433]: # Visit http://www.monetdb.org/ for further information 2015-10-06 16:02:19 MSG quantbox[3433]: # Listening for UNIX domain connection requests on mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock 2015-10-06 16:02:19 MSG quantbox[3433]: # Start processing logs sql/sql_logs version 52200 2015-10-06 16:02:19 MSG quantbox[3433]: # Start reading the write-ahead log 'sql_logs/sql/log.4' 2015-10-06 16:02:19 MSG quantbox[3433]: # Finished reading the write-ahead log 'sql_logs/sql/log.4' 2015-10-06 16:02:19 MSG quantbox[3433]: # Finished processing logs sql/sql_logs 2015-10-06 16:02:19 MSG quantbox[3433]: # MonetDB/SQL module loaded 2015-10-06 16:02:19 MSG merovingian[809]: proxying client 10.1.10.101:40633 for database 'quantbox' to mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock?database=quantbox 2015-10-06 16:02:19 MSG merovingian[809]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying 2015-10-06 16:05:19 MSG merovingian[809]: proxying client (local) for database 'quantbox' to mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock?database=quantbox 2015-10-06 16:05:19 MSG merovingian[809]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying 2015-10-06 16:05:27 MSG merovingian[809]: proxying client (local) for database 'quantbox' to mapi:monetdb:///var/lib/monetdb/quantbox/.mapi.sock?database=quantbox 2015-10-06 16:05:27 MSG merovingian[809]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying 2015-10-06 16:05:48 MSG merovingian[809]: database 'quantbox' (3433) was killed by signal SIGSEGV 2015-10-06 16:05:59 MSG merovingian[809]: starting database 'quantbox', up min/avg/max: 0s/0s/0s, crash average: 1.00 0.30 0.10 (3-0=3) 2015-10-06 16:06:00 MSG quantbox[3532]: arguments: /usr/bin/mserver5 --dbpath=/var/lib/monetdb/quantbox --set merovingian_uri=mapi:monetdb://qbdb:42000/quantbox --set mapi_open=false --set mapi_port=0 --set mapi_usock=/var/lib/monetdb/quantbox/.mapi.sock --set monet_vault_key=/var/lib/monetdb/quantbox/.vaultkey --set gdk_nr_threads=4 --set max_clients=64 --set sql_optimizer=default_pipe --set monet_daemon=yes