templated roles are not added automatically if missing after upgrade

Fails at the last hurdle deleting a project group on an instance that had been upgraded from an old version:

org.apache.maven.continuum.ContinuumException: error removing tempalted role for project Maven
at org.apache.maven.continuum.core.action.RemoveAssignableRolesAction.execute(RemoveAssignableRolesAction.java:78)
at org.apache.maven.continuum.DefaultContinuum.executeAction(DefaultContinuum.java:2432)
at org.apache.maven.continuum.DefaultContinuum.removeProjectGroup(DefaultContinuum.java:261)
at org.apache.maven.continuum.web.action.ProjectGroupAction.remove(ProjectGroupAction.java:184)

I suspect this is an indication of a bigger problem that the missing templated roles are not added automatically if they are missing.