After configuring OpenSSO Enterprise against an existing schema (DIT) , you cannot log in to the console, because the encryption key entered during the configuration (the one from the old Access Manager or Federation Manager instance) is not used. Instead, a new incorrect encryption key is generated, which creates an incorrect serverconfig.xml file.
Change to OpenSSO Enterprise config directory.
Change the encryption key in the AMConfig.properties file with the correct value.
Copy the backup copy of serverconfig.xml from the previous Access Manager or Federation Manager instance.
Restart OpenSSO Enterprise server.