I got these results for both tests Sargan and Hansen are used to test the overall validity of the instruments.

How to interpret the results?

Sargan test of overid. restrictions: chi2(78) = 147.74 Prob > chi2 = 0.000

(Not robust, but not weakened by many instruments.)

Hansen test of overid. restrictions: chi2(78) = 16.30 Prob > chi2 = 1.000

(Robust, but weakened by many instruments.)

Thank you very much for your supports.