After upgrading to LAC 4.1 you may notice functionality problems.
If running on Postgres or MySQL (but not Oracle), and you have at least one rule of type: sum, count, formula, parent replicate, min, or max, and that rule is incomplete and does not have its attribute defined (i.e: the rule was most likely created but never completed), then migration will fail with errors similar to the below:
Exception while initializing admin data, SQL was: alter table "rules" alter column "name" set NOT NULL
alter table "rules" alter column "name" set NOT NULL
java.lang.RuntimeException: org.postgresql.util.PSQLException: ERROR: column "name" contains null values
It is very important to ensure you have a backup of your admin database prior to the upgrade. If this issue is encountered you will need to restore the backup, fix or delete the offending rule(s) and perform the upgrade again.