If you manage multiple servers and the license key fails during an automated script, use the command-line tool VisualSVN-Server.exe :

: You must first disable Enterprise-only features like Windows Authentication or VDFS replication before this switch will work. Maintenance Renewal

If you have a perpetual license, the software never stops working. However, you are only entitled to install versions released before your maintenance ended. If you upgrade to a newer version of VisualSVN Server, your old key will be rejected.