Check and make sure you downloaded the latest java.
Are your scripts out of date? Try removing them and adding them back.
Still not working? Then chances are, you have java 1.8 installed. Osbot does not work with java 1.8.
Go to the control panel on your computer, go to "uninstall a program", and look for java. Look for java 1.8 or java 8. Pretty much you want to uninstall anything that isn't java 7 update 51.
After you've done this, load Osbot. If you get an error saying "failed to inject client", close out and retry. Keep retrying, it should work eventually.