I deployed a webtop 6.7 to the weblogic 12.1.1.0 Admin server and started receiving the DM_DFC_E_BAD_CLASS when attempted to login to the webtop.
This is on my local Windows 7 machine where which has the DFC 6.5 installation.
Solution:
for my case the solution was to remove the environment %CLASSPATH% variable form the System as the weblogic startup script uses the system classpath in the way that it may override your application's classpath:
-Dlaunch.class.path="%CLASSPATH%"
I'm personally new to the Weblogic world.
Perhaps someone could recommend a more "elegant" way to deal with this.