Following NetScaler - License Activation Service, you may see below error in step 3: No supported entitlements are available for activation.

You may also see the same error in step 2 and `instance` and `type` boxes have no options for you.

This error is general and may have multiple possible causes. For examples:
1. Citrix Operations team is actively converting all perpetual licenses to the subscription model in the licensing systems. You can login to your Citrix account to check.
2. Make sure the activation request file is generated on the correct endpoint (the license owner).
If you cannot see a subscription / fixed term bandwidth license under your account, or everything is valid, you still get the error. Please reach out to Citrix Support.
This article describes a typical issue during LAS transition: No supported entitlements are available for activation