It can happen that you need to downgrade the AOS kernel in a system. Depending on the build you are going back to, you might get an error message.
Object Server 01: Fatal SQL condition during
login. Error message: “The internal time zone version number stored in the
database is higher than the version supported by the kernel (4/1). Use a newer
Microsoft Dynamics AX kernel.”
You need to change the value for the column value SYSTIMEZONESVERSION in the table SQLSystemVariables. If you look in
the event viewer you can see that it finds the value 4, but expected 1 (4/1).
So the solution is to change the value to 1.