Before I went to a mechanic to certify the car, it was working just fine, this problem had not occurred at all. The car could be driven just fine with no problems. However, once I had to go to a mechanic to certify the car, they said that a few things had to be fixed. I thought that was acceptable, but once they fixed it, and I came to pick it up, it wasn't able to start precisely because of this flashing green key light on the dashboard that showed up.
The mechanic was able to get it working once by placing the key in the ignition and turning on and off the ignition a few times, but once I came home with the car, it stopped working the day after, and the flashing green key light on the dashboard still shows up. I had a locksmith come and look at the car and they said it was a problem with the car for some reason.
I have exactly the same problem when I use my spare key.
What can I do to fix this issue?