When an Enterprise license expires (or the license key becomes corrupted), TeamCity reverts to working in Professional mode. This means that certain features will be disabled or have a limited functionality and builds will not run unless a number of stipulations are met. For details on TeamCity Professional's limitations, please see editions.
tip
TeamCity preserves your Enterprise settings when you downgrade to the Professional version. However, if you have to remove user accounts or build configurations to work in Professional mode, it is recommended you make a backup of the TeamCity Data Directory to use when returning to the Enterprise mode.
Feature Changes when Reverting from Enterprise to Professional Editions
Roles
System and Project Administrators get Administrators role. (TeamCity actually checks to see if the EDIT_PROJECT permission is present in the user's account).
Project Developers and Agent Managers get to Users role.
Guest users, regardless of how they were configured in Enterprise mode, will only be able to view the projects.
NT and LDAP Authentication schemes are not supported in Professional mode. If you were not already using TeamCity's default authentication scheme, up to 20 TeamCity users will need to have new accounts created for them using this scheme.
After you provide a valid Enterprise license, all feature limitations will be removed and:
Enterprise user roles and permissions are preserved while running in Professional mode and restored automatically
Users created while working in Professional mode will be assigned the "Default User" settings when switching to Enterprise
tip
If you made a backup of your TeamCity Data Directory because you had more than 20 build configurations or users, and you ran builds in Professional mode, you will want to back up your current TeamCity Data Directory to preserve your most up-to-date build information. Restore the original "Enterprise" backup before entering your Enterprise license, then manually copy the specific build folders from the more recent "Professional" backup.