Use the Sentinel Admin Control Center to diagnose Error 30:

If the key appears in the Admin Control Center but ETABS still throws Error 30, the problem is within ETABS itself – apply Step 4 (Run as Admin).

In simple terms, Error 30 means ETABS opened, looked for the license server or local license file, found something, but didn't recognize it as valid. This usually happens due to:

Before attempting fixes, understand the root causes:

If a Windows update caused Error 30, residual registry keys are the problem.

CSI provides a utility specifically designed to reset the license recognition state. This resolves ~70% of Error 30 cases.

Do not assume your USB dongle (Hardware Key) works just because the light is on. Remove the dongle from the USB port.