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.
I ran into this same issue, and the problem was caused by the Grails installation it was trying to use. It wanted to use the default version that comes with GGTS rather than the one I installed myself.

To fix, go to Window > Preferences > Groovy > Grails, then "Edit" the Grails installation it shows. I had to switch mine from `C:\ggts-bundle\grails-2.4.4\` to `C:\grails-2.4.2\`.