In my experience, the old RDC object model can work fine on the latest platforms (though it may require a couple of tweaks).
Manually registering dlls is a red flag. You must let the Merge Modules take care of the runtime install.
I'm not sure I understand the reference to: "Version 8 e Version 11." Do you mean Version 8 and version 11? For your scenario, you should move to 11.5 (XI R2) and use the latest SP.
But to more easily isolate the issue, install Crystal 11.5 (XI R2) Designer first and see if it can run the report on that platform against your data source.