Got [500 Internal Server Error] error when do calling api https://user-lib.temcocontrols.com/auth

[qnst]

1. Open the T3000 application, click "Show Webview Graphic" to open the integrated HVAC Drawer. Log in the system by clicking the "LOGIN" button.

2. The system will redirect me to the login page [https://user-lib.temcocontrols.com/auth?token=5b096b95b679aa1&user_id=13559&cid=1450662973&path=auth], and show an error message [{"name":"Error","message":"The user does not exist!"}] with status= [500 Internal Server Error].

3. But it's OK to log in to https://temcocontrols.com with the same account.

4. This error will prevent users from uploading images in the HVAC graphic drawer when they have previously logged in with existing cookies.
   Same error response when calling https://user-lib.temcocontrols.com/hvacTools. The user is blocked from uploading.

Q1: How to check the log details on the server side with such errors? Do I need to log in to the server?
Q2: Which repo contains the source code of this API?
Q3: Where has the API been deployed?
Q4: Can I have an account to log in to the server?

Please help to take a look at this, Thanks!