How to debug error relating to SIGNAL MISMATCH IN SIMULATION BLOCK

The error generated from the simulation file are itemised below

Error occurred during model compile.

Complex signal mismatch. Input port 2 of 'Bro_sam_project/Error Rate Calculation2' expects a signal of numeric type complex. However, it is driven by a signal of numeric type real

Complex signal mismatch. Output port 1 of 'Bro_sam_project/General QAM Demodulator Baseband1' is a signal of numeric type real. However, it is driving a signal of numeric type complex

Simulation file

Please help with debugging the attached file.

Thanks