HSQL database is shared between users
Kepler starts an HSQL database server so that multiple instances of Kepler can run on the same machine. (For more info on this, see bug 2315). However, this is problematic on machines shared by
different users: the server started by the first user is accessed by subsequent Kepler instances run by other users. (This causes several problems including: the actor tree displayed in subsequent Kepler instances displays the actors in the suite of the first instance, the default directory for File->Open in subsequent Kepler instances belongs to the first user, etc.).
To fix this bug, different database servers should be started for different users to prevent sharing. Additionally, the same database server must be used for multiple instances of Kepler ran by the
same user otherwise the database files will be corrupted. (Note that a single Kepler instance may run three different servers: one for the cache, one for LSID stuff, and one for provenance. None of these should be shared between different users).