List of returned errors:

0: No errors – there are no errors

1: Signing in failed – incorrect Login / Password entered

2: Authorization required – authorization is required to access the data

3: Dead session number – session has expired, re-authorization is required

4: Bad interval – incorrect time interval entered

5: Bad object – there is no object with this identifier

6: Admin login – someone is trying to log in as Admin User

7: Unusable object – the value cannot be calculated for the object with this identifier

8: Bad event type – there is no event type with this identifier

9: Access denied – no authorization to access the object

10: Data not found – no data for the corresponding input values

11: Blocked interval – the requested interval contains data blocking periods

12: Bad object type – the specified object type does not exist

13: Invalid format – the format is incorrect

14: Undefined error – the error is unspecified

15: 404 – page not found