Error migrating 4.3 to 5.08

Hi there,

while migration of a Plone site from 4.3 to 5.08 I get the following error:

ConstraintNotSatisfied: (u'site_actions', 'category')
End of upgrade path, main migration has finished.
The upgrade path did NOT reach current version.
Migration has failed
Dry run selected, transaction aborted

Does anyone know how to fix this?