# Troubleshooting and list of error codes

## Working  with errors

This section captures a list of common HTTP errors you might encounter and possible solutions to fix them.

| HTTP Error Code | Error Text | Reason | Possible Fix |
|  --- | --- | --- | --- |
| `HTTP 401` | Access denied | The  credentials provided in the request was not sufficient for a successful authentication check. | To fix a failed authentication request, see the [Authentication page.](/connectivity/docs/authentication/#troubleshooting) |
| `HTTP 403` | This account doesn't have access to this property   | Possible reasons are, you are trying to send updates:  - for a property with the wrong hotel ID. - using machine account that do not have access to the specified hotel ID.  - for a property which is no longer in active connection status with your interface. | Make sure to specify the correct hotel ID or check your machine account credentials. You can then follow the steps:  1. Check if the property is connected to you in the [Provider Portal](https://connect.booking.com/hotels).  2. Check if the connection status is active in the ‘**Properties**’ tab in the [Provider Portal](https://connect.booking.com/hotels), using the property ID.   3. Check if the property is added to the machine account you use under ‘**Machine Accounts**’ in the [Provider Portal](https://connect.booking.com/hotels).  To know more about how to use the [Provider Portal](https://connect.booking.com/hotels) for the above actions, take a look at this [self-help guide](https://portal.connectivity.booking.com/s/article/A-guide-to-self-help-options-in-the-Provider-Portal?language=en_US). |
| `HTTP 500` | Internal server error | Possible reason may be that Booking.com systems are experiencing temporary outage. | Try calling the endpoint after some time. |