I came across a similar error in My webMethods when trying to configure Metadata Library. More than likely, I assume you either re-installed My webMethods or dropped and re-created your My webMethods database using the DB configurator.
If this is the case, then you need to do the following.
drop your My webMethods database again using the DB configurator
manually delete all tables and sequences starting with CCS in your database
re-create your My webMethods database using the DB configurator.