Should you find your characters unable to zone into any other different areas, you can generally fix the issue by completely logging out and logging back into your client.
If this does not solve the issue, you may have a few corrupted zone files. For this you simply need to place an In-Game Appeal in regards to being unable to Zone, and a CSR will contact you as quickly as they can.
Before you reach the CSR, you may wish to locate the folders "Zones" and "Frontiers" in your Dark Age of Camelot Folder. These folders will be necessary once you've come into contact with a CSR.
Should you be unable to reach a CSR for any reason, you can also attempt to fully delete the "Zones" and "Frontiers" folders. Upon logging back into your DaoC client, the game will patch and replace all of the missing zone files. ( The downside to this being, to replace all the files will take a bit of time. )
If even after this, the issue continues to persist you may need to contact the Technical Support department at: 650-628-1001.
They are open Monday through Sunday, between 10am and 10pm EST.
If you are unable to contact them by phone, you can also send an email to: support@darkageofcamelot.com.