When Licensing node is selected in Studio: Error You have read only access to the license server.
The Authentication token (HTTP Authorization Request header) is very big and crosses the limit of default request field size the Apache have. Based upon that, we assume that user is part of many Groups.
Add following line in httpd.conf (C:\Program Files (x86)\Citrix\Licensing\WebServicesForLicensing\Apache\conf) anywhere below header policies and restart the Web Service for Licensing Service
LimitRequestFieldSize 15360
Add below this line: Header set X-Content-Type-Options nosniff