1. The size of the repository and web catalog might affect the start up times of the services. Remove any obsolete items from the repository and web catalog. Run the process of validating the catalog as per documentation.
2. If logging was enable to the TRACE (finest). This caused the Presentation Server to take a very long time to start (15 minutes) and in turn cause OPMN to timeout which threw an error in Enterprise Manager
1.Navigate via Enterprise Manager Fusion Middleware Control > coreapplication > Diagnostics tab: Log Configuration sub-tab
2.Press Lock And Edit Configuration
3.Set 'Trace' to 'OFF'
5.Click 'Activate Changes'
6.Click 'Restart to apply recent changes'.