You likely have a corrupt license file ( .lic ) on the server. You will need to contact CSI Support or your local distributor to re-host your license (generate a new license file based on your server's "Fingerprint" or "Locking Code").
If the issue persists, the following steps are recommended by users on CSI Knowledge Base Run StandaloneKey.exe etabs license error 18 2021
For (most common for error 18):
: Ensure your hardware's HostID hasn't changed (e.g., due to a new network card or motherboard), as the license is often locked to specific hardware. Check for "Nulled" Software Issues You likely have a corrupt license file (
“The 2021 build?” He yawned. “Did you try restarting the license service?” etabs license error 18 2021