Why can't I open up AWS Server Explorer Tool Window?

I downloaded the AWS plugin: http://plugins.jetbrains.com/plugin/?idea&id=4558    
and am following the documentation steps: https://docs.google.com/document/d/19hE4N2ctSeU9Pdb7CHCucMG3qeqPNwp1gsnb0IAsLJ8/edit#heading=h.6624dab243e9

In step 4 under

RDS MANAGEMENT

1. Configure RDS.

it says to open up the tool window:

After steps 1-3 are successfully done the RDS appears in the AWS Server Explorer Tool Window (To open it go to Tools->Open Amazon WS Explorer).

But the option "Open Amazon WS Explorer" remains grayed out.

When I was following steps 1-3, I just created a default DB Parameter and Security group, and set my RDS to use that one. I seem to be getting this error when I click on Apply:

Error during dispatching of java.awt.event.MouseEvent[MOUSE_RELEASED,(1058,828),absolute(1515,850),button=1,modifiers=Button1,clickCount=4] on dialog28: java.lang.Integer cannot be cast to java.util.Date