The reason you are getting the error message is because iClone 2.5 is not compatible with Crazytalk 5. iClone 3 will be fully compatible with Crazytalk 5 when it is released next month.
If you also have Crazytalk 4.6 then you can continue to use that with iClone for now. Both CT4 and CT5 can run alongside each other without any problems.
Peter EdwardsForum Moderator
iClone Daily Blog