The newest GarageBand (GarageBand 10.0) does no longer allow to add effects freely, each patch as predefined effect setting.
Use the nice tool "GBEffectFinder", to see which patches will support the effects you need. Download GBEffectFinder here from Bullets&BOnes: http://www.bulletsandbones.com/GB/File%20Pages/GBEffectFinder.html
The EpicDiva will be available in GarageBand 10.0, if you did not uninstall GarageBand '11, when you updated. Then you find the old GarageBand patches in the "legacy" section, e.g. "Legacy > GarageBand > Voices > Epicc Diva".
The upgrader will have moved your GarageBAbd '11 to a subfolder of Applcations. If you did not uninstall it, you can still use it.
If you did not yet do it, use the command "GarageBand > Restore Purchase", if you previously owned an earlier version. Expanding GarageBand for Mac (v10.0) content with an in-app purchase
You can use both versions of GarageBand cuncurrently, the previous '11(version 6.0.5) and the new GarageBAnd 10.0. They do not interfere.