Errors in opening EE and EFDC_Plus_OMP.exe stop working

I met three errors in running EE8.4: 1.EFDC_Plus_0840_OMP.exe stop working (as pictures shown below). This error says the program encounters a problem which cause it to break, and it occurred when I was running dozens of cases at the same time using the multithreading. which lead to all the cases program abort. This error occurred when I was modelling water quality in 2017,but was rarely happened in modelling 2016. 2.Your licence was inappropriate. This error often occurred when I tried to open mutiple cases, which need to open EE many times. It seems the EE will check licence evvery time it was opened or just ran it. The windows defender had been shut down. 3.Could not activate, and access denied. Usually the method of reinstall EE was helpful to solve this erroe, but it often occurred next time. I think it may be correlated with the windows defender sacnning, but I have shut it down. I want to know is there anyway to solve these errors? Thank You!