IF you are having issues accessing OASIS due to a security issue with Java, try the following steps...
Either update to version 7 update 25
-Go to yoru Windows Control Panel
- Go to yoru Java Control panel inside of the windows control panel
- On the Security Tab, lower the security level to medium then apply the changes
Then return to oasis and you should be able to load the plugin and sign in.
This information provided by the Oasis webpage.