AirWave license keys are pretty big -- certainly too big to type manually -- and can be confusing. You should copy and past everything INCLUDING the lines with "Begin AMP License Key" and "End AMP License Key", and paste them into the field on the AWMS's Home -> License page.
Here's an example key:
--- Begin AMP License Key ---
Product: AWMS Enterprise
Organization: Nifty Business Group, Inc.
Expires_on: Wed Oct 29 22:02:38 2008 UTC
Generated: Tue Oct 28 22:02:38 2008 UTC by aY1gFG6Gst4ccSz43Jz+mQ
--- Signature ---
--- End AMP License Key ---
Accept the license terms.
If you are using temporary License key contact Aruba support with the IP address of the AWMS to obtain your permanent license key.