For those experiencing this common error, which shows up when there are null entries in the crafting skills for bot members, there is a simple fix.  Edit your my.ini file in your mysql install to comment out the current sql-mode= statement and add this one:

sql-mode=MYSQL40

then stop and restart your mysql service.
This forces the sql server to behave as it did in version 4.0 and earlier, and it will not display this error.