Can't resolve 1756-EN2TR network I/O Error

The controller is talking on a DLR network to 2 other I/O chassis which I can ping and connect to with RSLinx. But, Logix Designer keeps showing the yellow triangle on the network card and can't see it to reset any I/O errors.

The controller window displays "Object Mode Conflict". The firmware is the same and up to date. Any ideas?

Go to the module properties (the module working as ring supervisor), network tab, and look for the information on "ring fault" section.

nhatsen said:

Go to the module properties (the module working as ring supervisor), network tab, and look for the information on "ring fault" section.

Click to expand...

I checked the network properties for the ring supervisor, and it doesn't show any errors (neither does the DLR tool). I think the network is ok, but the controller and I/O rack are somehow incompatible (?) i.e. "Object Mode Conflict"
Downloadable .ACD project file: https://drive.google.com/open?id=0B_OlFNbBQXctX2ZYeVRpZnJBaWM