I recently upgraded to Cubase 8 from 7.5. Now when I select ezDrummer from my virtual instruments, it brings up ezDrummer 1. Several months ago I upgraded to ezDrummer 2 and was working fine in Cubase 7.5. How can I correct this problem?
It sounds like you have 2 different ezdrummer.dll’s, and perhaps in different locations. Do a Windows search and remove the old .dll. Then make sure the new .dll is in the location you want it to be…probably with dozens or hundreds of other .dll’s. If that still doesn’t work, make sure in VST plug ins that you have created a path to that .dll.
You didn’t mention your system specs but if using CB with a windows OS for some reason CB 8 is looking at the old EZD1 “EZdrummer.dll” file.
Open CB 7.5 and go to devices>plug-in information. Look for ezdrummer in the list of vst plug-ins. Make note of the path the “EZdrummer.dll” file is installed in. This should be the EZD2 .dll file.
Now open CB 8 and go to devices>plug-in manager. Look for ezdrummer in the list of vst instruments. Click on it to note the path of the “EZdrummer.dll” file which will show in the lower portion of the screen named “Plug-In Information” (you may have to click on the “I” icon to see the path). This should be the EZD1 .dll file.
The EZD1 and EZD2 EZdrummer.dll files are named the same but the date is different. So if you want EZD2 just copy the EZdrummer.dll file from the path location you noted in CB 7.5 to the path noted in CB 8 and you should be all set.
Note, again, you will be overwriting the old file with the new .dll file as they are named the same. IMO Toontrack should have named them differently. Oh well. 
Regards 