Steps to reproduce:
1)Update Glass fish certificates.
2)Create a web application.(Go to File->New->Web->Web Application)
3)create a web service by right clicking web application node. 
4)Right click the web service and select Edit web service attributes.
5)Enable Secure All Service Operations.
6)Select Endorsing certificate form the drop down list.
7)Click on Trust store button.
8)We are able to see Alias drop down list and Load Aliases button is
disabled(Greyed out)

Expected result:Alias drop down list and Load Aliases button should be activated
 as the Alias for the endorsing certificate mechanism will be the alias is
xws-security-server.

Attaching the screen shot of the same.