If you impersonate an external user in the Work Center shell using the " Log On as" feature, you will find you cannot continue to log on as any other user except for yourself. In the classic Workspace shell, you are able to do this just fine.
This error is caused by the First Name, Last Name or Login name having a special character in it like a double quote. To avoid this error login as an admin and remove any special characters such as double quotes from the users name in the Manage Users area.
If a database upgrade is taking a long time due to data migration, other migration issues will occur if trying to release the database lock prematurely. To remove the lock, log in to the Pulse database and update the DATABASECHANGELOGLOCK table to remove the lock : sqlplus pulse/pulse@<sid>
