Upgrading confluence from 2.5 to 2.7.4 getting UnexpectedRollbackException error

[jyoti ck]

While Upgrading confluence from 2.5 to 2.7.4 getting following error:

ERROR [http-8080-Processor25] [opensymphony.webwork.dispatcher.ServletDispatcher] serviceAction Could not execute action
-- url: /confluence-2.7.4/dashboard.action | userName: testadmin | referrer: http://localhost:8080 /confluence-2.7.4/login.action?os_destination=%2Fhomepage.action

org.springframework.transaction.UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:626)

[Abdoulaye Kindy Diallo]

May be you could try to redo this step by step: 2.5 to 2.6 if successful then from 2.6 to 2.7.

Hope that helps !!!