After returning to a pre-12.5.4 binary:
When returning to 12.5.0.x or earlier, the new datatypes date, date null, time, and time null remain in systypes but you cannot use them in 12.5.0.3 and attempts to use them in 12.5.0.2 or earlier will cause a stack trace. See the special procedure for downgrading to Adaptive Server version 12.5.0.x to avoid problems with new datatypes.
sp_values is dropped and re-created when you run the 12.5.x installmaster, so any new types are eliminated from this table.
sysmessages still contains all the new error messages, but that is not a problem because they are not used.
