Question: I installed a fresh copy of GGTS on a fresh copy of windows 8 with JDK 1.7 installed.  

I tried to get it to compile my existing project which was based on 2.3.6 and it failed miserably as GGTS comes with grails 2.4.2. 

I know serveral people who had problems with 2.4.x so decided to stick with 2.3.

So I downloaded 2.3.11 (latest 2.3) and created a GRAILS\_HOME pointing to 2.3.11 dir, and JAVA\_HOME pointing to the root of the JDK.

On command line, I can now type grails - version and get back 2.3.11.

I restarted GGTS, and deleted the project and createde it again, adding 2.3.11 as a new Grails version, and set the project to use that.

It fails to compile, saying version is wrong. Fair enough. But when I try to launch the command line from GGTS using the gree circular button at the top which looks like 3 cups, it says:

```
Retrieving available scripts
Retrieving available scripts
An internal error occurred during: "Retrieving available scripts".
java.lang.NullPointerException

```

Any ideas?

Answer: 
In my case the problem was, that I had moved grails to a different folder. I just had to change the location of grails in the settings. Hope that helps somebody.
**check** all grails-project's '`app.grails.version`' in `application.properties`, then open window - preferences - groovy -grails, make sure that **all** VERSIONs were defined ( I use sts, maybe a little difference ).

alternatively

**update** all `application.properties` set `app.grails.version=2.3.11` ( the version your ggts defined )