Deep breath, eyes wide open.
Because you can use the Autoconfig feature and the controller appears in an RSLinx/RSWho browse, that is good news and indicates the controller's not totally busted.
Usually "incompatible processor" means that the controller has firmware that RSLogix 500 doesn't recognize. Usually that means the controller is newer than RSLogix 500.
Let's examine your version of RSLogix 500 (the current release is version 7.3) and the firmware revision of the controller.
Check the label on the bottom of the controller (the shipped Firmware number should be right next to the "Series A Rev B" label).
Unfortunately RSLinx doesn't show the firmware revision of the controller, only RSLogix 500 does and it's not cooperating right now.
RSLinx does show the controller's program name (empty controllers are called UNTITLED) and the controller mode (mine is in Remote Program right now, yours may read Faulted).