I am using Spring STS 2.9.1 when I encountered an issue where the Plugin Manager was refusing to show up
My first instinct was to try a newest release of Spring STS which at the time was 3.0.0.M1
I downloaded and installed it, and was able to successfully open the plugins manager. YAY!
At first, I thought I was finished and ready to continue coding. Then when I went to open up a file, just about any file, I get a NullPointerException. I realized this version had it's own set up problems, that I was not ready to deal with.
I returned back to version 2.9.1 and found a way to patch it up. The solution is below:
I managed to find a patch with a fix to the "Grails support" extension from a nightly build. To do this, in the STS menu select:
Window -> Preferences -> Install/Update-> Available software sites
Under "Available software sites" add the following sites:
To activate the update process do the following:
Help -> Check for Updates
Follow the instructions to perform the update and restart STS.
And your good to go!