Question Trying to use exe environment to train using python mlagents

Hi community. As a beginner, I'm trying to learn to use a custom exe environment to train an agent. I found this repo to train in the tennis environment. It runs fine. So, I decided to create a simple custom environment and use the repo implementation. I followed the instructions here and created an exe following this from UNITY. But when I try to use this custom environment, I get the error-
"The unity environment took too long to respond"
I tested the environment on unity (running it using the mlagents package) and it responds fine there. I am kinda confused and it is getting difficult for me to understand the problem. Any help would be really appreciated. Thanks in advance.