I have the same problem I have tried following this advice but every single day for the last 3 months its just said "authentication error occurred" but then on my laptop, my Xbox and my families' smartphones they all have a strong connection. Also when I have a look at the signal strength it still says very strong????

Why can wifi of my work place can't connect with my mobile. it connect with others, and my my device also connected with other network

Have you tried connecting other devices to your Wi-Fi network? If other devices can connect without any problem, it could be your device that has a problem. Restart your phone then try to connect again. Make sure you enter the correct password.

Let me know how it goes.