JM 2.3.1 database is already in use by another process

I have upgraded Jive Messenger from 1.5 to 2.3.1 and use the embedded-db. The admin console works fine, but I am receiving many errors in the Jive Messenger server start-up window.

Here is an example:

Failed to create new connections on startup. Attempt 0 of 3

java.sql.SQLException: The database is already in use by another process: org.hsqldb.persist.NIOLockFile@b27997b8[file =C:\Program Files\Jive Messenger\embedded-db\messenger.lck, exists=true, locked=false, valid=false, fl =null]: java.lang.Exception: The process cannot access the file because another process has locked a portion of the file : C:\Program Files\Jive Messenger\embedded-db\messenger.lck

at org.hsqldb.jdbc.Util.sqlException(Unknown Source)

at org.hsqldb.jdbc.jdbcConnection.(XMPPServer.java:134)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

at java.lang.reflect.Constructor.newInstance(Unknown Source)

at java.lang.Class.newInstance0(Unknown Source)

at java.lang.Class.newInstance(Unknown Source)

at org.jivesoftware.messenger.starter.ServerStarter.start(ServerStarter.java:82)

at org.jivesoftware.messenger.starter.ServerStarter.main(ServerStarter.java:46)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)

at com.exe4j.runtime.WinLauncher.main(Unknown Source)

Any ideas what would be locking my database files?

Thanks for any help. Iā€™'ll be glad to provide more information if needed.

I misspoke ā€“ I upgraded from 2.1 to 2.3.1.