ERROR 18452: The User is not associated with a Trusted SQL Server Connection

This can occur due to one of the following reasons:

1: If SQL Server has been configured to operate in “Windows Authentication mode” and doesn’t allow the use of SQL Logins.
Resolution: Change the Authentication mode from “Windows Authentication mode” to “Mixed Mode”(SQL SERVER and “Windows Authentication mode”)

2: You are trying to connect using SQL Server Authentication but the login used does no t exist on the SQL Server.

3: The login could have been using windows Authentication but the login is an unrecognized windows principal. An unrecognized windows principal means that the login cannot be verified by windows. This could be because the windows login is from a domain not trusted by the server. In this case do the following to determine if there is a trust between the client and the server.
PING: The Server on both IP and Name from the Client.
PING: The Client on both IP and Name from the Server.