This morning, while adding a new user to the system as "admin", I received the following error:
Failed to create Person due to error: Transaction didn't commit: Failed to prepare: requires rollback
Unfortunately, I cannot locate much help via the web and the only heavily active thread was in French I found one thread encouraging someone to upgrade, but we're using the stable 2.1 version.
Prior to this error, there were two changes made that might be the cause - but I'm not sure. First, we removed the "EVERYONE" permission from the Data Dictionary and only made it available to Admin. The second change was to disable the 'Inherit Permissions' option on the Users space.
Since encountering the error, I've reimplemented these by adding EVERYONE back and enabling the Inheritance option. Unfortunately, I'm still getting the error.