Hello, folks:

I am new to ManifoldCF, and trying to make my own connector.
For now, I could successfully build ManifoldCF including my own connector.
However, when I tried to run, I have exceptions.

The exception I am facing is :

org.apache.manifoldcf.core.interfaces.ManifoldCFException: integrity constraint violation: unique constraint or index violation: I1549774667196
        at org.apache.manifoldcf.core.database.DBInterfaceHSQLDB.reinterpretException(DBInterfaceHSQLDB.java:734)
        at org.apache.manifoldcf.core.database.DBInterfaceHSQLDB.performModification(DBInterfaceHSQLDB.java:754)
        at org.apache.manifoldcf.core.database.DBInterfaceHSQLDB.performInsert(DBInterfaceHSQLDB.java:230)
        at org.apache.manifoldcf.core.database.BaseTable.performInsert(BaseTable.java:68)
        at org.apache.manifoldcf.crawler.connmgr.ConnectorManager.registerConnector(ConnectorManager.java:172)
        at org.apache.manifoldcf.crawler.system.ManifoldCF.registerConnectors(ManifoldCF.java:672)
        at org.apache.manifoldcf.crawler.system.ManifoldCF.reregisterAllConnectors(ManifoldCF.java:160)
        at org.apache.manifoldcf.jettyrunner.ManifoldCFJettyRunner.main(ManifoldCFJettyRunner.java:239)
Caused by: java.sql.SQLIntegrityConstraintViolationException: integrity constraint violation: unique constraint or index violation: I1549774667196
        at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
        at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
        at org.hsqldb.jdbc.JDBCPreparedStatement.fetchResult(Unknown Source)
        at org.hsqldb.jdbc.JDBCPreparedStatement.executeUpdate(Unknown Source)
        at org.apache.manifoldcf.core.database.Database.execute(Database.java:916)
        at org.apache.manifoldcf.core.database.Database$ExecuteQueryThread.run(Database.java:696)
Caused by: org.hsqldb.HsqlException: integrity constraint violation: unique constraint or index violation: I1549774667196
        at org.hsqldb.error.Error.error(Unknown Source)
        at org.hsqldb.error.Error.error(Unknown Source)
        at org.hsqldb.index.IndexAVL.insert(Unknown Source)
        at org.hsqldb.persist.RowStoreAVL.indexRow(Unknown Source)
        at org.hsqldb.persist.RowStoreAVLDisk.indexRow(Unknown Source)
        at org.hsqldb.TransactionManagerMVCC.addInsertAction(Unknown Source)
        at org.hsqldb.Session.addInsertAction(Unknown Source)
        at org.hsqldb.Table.insertSingleRow(Unknown Source)
        at org.hsqldb.StatementDML.insertSingleRow(Unknown Source)
        at org.hsqldb.StatementInsert.getResult(Unknown Source)
        at org.hsqldb.StatementDMQL.execute(Unknown Source)
        at org.hsqldb.Session.executeCompiledStatement(Unknown Source)
        at org.hsqldb.Session.execute(Unknown Source)
        ... 4 more


I am guessing my class-path would have a problem, but do not have a confidence. 
What is the cause of this error?

I would appreciate for any of your help.


Sincerely,
Kaya