Steps to reproduce:
1) Install Liferay 6.2.0 CE GA1 on system A (server)
2) Using web browser on system A, visit http://localhost:8080/ > Server Administration > Script, click Execute
3) Observe the script runs and returns the correct results
4) On system B (client), visit http://ip-of-system-B:8080/ > Server Administration > Script, click Execute
5) Observe the script runs and returns the correct results
6) Update hosts file on system B (client) with "ip-of-system-A testhost.domain"
7) Visit http://testhost.domain:8080/ > Server Administration > Script on testhost.domain using web browser on system B, click Execute
8) Observe the script does not execute correctly and catalina.out contains "14:28:37,805 ERROR [http-bio-8080-exec-56][PortletRequestProcessor:466] Forward does not exist"
The problem seems to be that if you access Liferay with any hostname other than the one on the server, Server Administration > Script execution fails. Since our organization accesses a Liferay cluster through a load balancer with multiple virtual hosts (www.domain.com, secure.domain.com, intranet.domain.com, etc), the hostname used to access Liferay never matches the hostnames on the individual cluster nodes, so Script functionality is unavailable unless we bypass the load balancer and access Liferay using one of the nodes directly.