Using sp_downgrade_esd on an Adaptive Server 15.7 ESD #2 database allows you to load it into Adaptive Server 15.7 or 15.7 ESD #1.
If you have a database in Adaptive Server version 15.7 ESD #2 that you want to open in Adaptive Server 15.7 or 15.7 ESD #1, you can downgrade it with sp_downgrade_esd temporarily to perform the dump and load, after which you revert the database so that it is usable in the current version of Adaptive Server again.
Perform these one database at a time, and only for the databases you want to open in an earlier version of Adaptive Server 15.7.