To fix this issue, ensure the Static Content is enabled under Common HTTP Features on your IIS server. This is easily accomplished by entering the following commands into PowerShell:
> import-module servermanager
> add-windowsfeature web-static-content
If this doesn't solve the issue, there may be an error with the identity used by the application pool. If you're using Windows Authentication in the SQL connection, verify that the application pool is running under the specified account, and the account has read access to the AlertManager directory on your IIS server.
If this doesn't solve the issue, please contact firstname.lastname@example.org.
Alert Manager is licensed against a Lync® pool. If you have 3 Lync® Pools, and you will need to send alerts to users in all pools, then you will need to license 3 Alert Manager servers.