Hello,
you have cables connected to fa0/0 and 1/0. What’s the other interface module? Is it serial or fast Ethernet? Also is the other port you’re trying to connect it to the same module type? I needs to be the same.
Finally are you using the correct cable such as serial or crossover or straight through. Id test different ones. But the interfaces need to match. Packet tracer tends to be pretty particular.
-David
