The errors in localhost.*.log suggests that there are multiple server instances attempting to open the same database.
The default access method to hsql as configured in the context file (using a jdbc:hsqldb:file:/... url) runs the database engine in standalone mode which allows a single process to access the database.
Make sure that other processes do not access the same database (=same path) - these may be any of the following: other context files in the same tomcat, other tomcats processes, or a studio's embedded server.
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