I was just testing a 4 bit binary synchronous counter (74161 IC) fed into a decoder (74154 IC), but as the decoder provides inverted outputs , I further passed the decoder outputs through a custom IC (the rightmost IC in pink colour), which I made out of 16 NOT gates. However, it's not getting simulated and displaying some error. The circuitry along with the errors are attached . Please help me rectify the errors.

 

I was just testing a 4 bit binary synchronous counter (74161 IC) fed into a decoder (74154 IC), but as the decoder provides inverted outputs , I further passed the decoder outputs through a custom IC (the rightmost IC in pink colour), which I made out of 16 NOT gates. However, it's not getting simulated and displaying some error. The circuitry along with the errors are attached . Please help me rectify the errors.

The error implies the 16 inverter IC library part does not have pins defined correctly.
Try using three 7404 hex inverter IC’s.