I recently installed SpringSource Tool Suite. And I want to start working with Grails projects. So, I went to the Dashboard -> Extension, where I saw two extensions: Grails (current production release) and Grails Support as in the image below.

But when I try to install them, I get the following errors :
Problems occurred while performing installation: Operation details
Operation details
Cannot complete the install because one or more required items could not be found.
Software currently installed: Shared profile 1.0.0.1340820181092 (SharedProfile_com.springsource.sts.ide 1.0.0.1340820181092)
Missing requirement: Shared profile 1.0.0.1340820181092 (SharedProfile_com.springsource.sts.ide 1.0.0.1340820181092) requires 'org.maven.ide.eclipse [1.0.100.20110804-1717]' but it could not be found
What can I do to resolve this error ? Or are there any other options I can follow to install Grails extension?
Thank you!
Yes, what @BurtBeckwith said. You should move to the new GGTS.
However, to address your particular problem, you installed STS into a read-only directory (or in C:\Program files). You need to re-install it somewhere else.
The Eclipse p2 installer cannot handle installing feature patches into a read-only directory. Groovy-Eclipse ships with a feature patch to extend the JDT compiler. I believe that this problem was fixed in the Juno release of Eclipse (4.2), which came out last week.