I had the same error and support suggested we stop tomcat, and restart MySQL. Open terminal and login to mysql

enter the following command to repair the Database

mysqlcheck --repair jamfsoftware -u root -p

This should repair all the tables in the database and return an OK status if it completed successfully. Look for the downloadable_file_chunk_data table. If the repair goes through successfully, restart Tomcat and see if the JSS loads

hope this helps
Dan

thanks ill give it a shot now

Thanks - can confirm this does solve the issue.

See also: http://derflounder.wordpress.com/2014/02/01/fixing-caspers-mysql-database-with-mysqlcheck/