In order to use Windows Authentication or you receive the error below: 

The issue is happening because authentication to SQL Server failing and this is due to two reasons:
  1. SQL Username and Password were not provided.
  2. If using NT-Auth - The olation service is not set to run as a user.

**When Olation Studio and Olation Web Services are uninstalled for an upgrade the "Log on as" is lost or changed. When the new build is installed the Olation Services "Log on as" is set to "Local System" rather than a specific user.


From the Start menu, select Settings, Control Panel, Administrative Tools.


Double-click on the Services icon


In the Services dialog box, locate Olation Server. Note: You must Stop service if it is already running. A stopped Service shows no Status, as in the figure below.



Double-click on Olation Server.

The Olation Server Properties dialog box appears, as shown in the following figure



Go to the Log On tab, select the radio button This account (circled in the succeeding figure), then select the Browse button.



In the succeeding Select User dialog box, select a User Account from the list. (e.g. User Name)

Select OK.

You are returned to the Olation Server Properties dialog box.




Now enter and confirm the <password> you specified when you created the user domain account.

Click OK.



 


A message box appears which states that the User Name has been granted Log On As A Service right.

Click OK.


Back in the Olation Server Properties dialog box, under the General tab, click the Start button to start Olation Server



When you go back to the Services dialog box, note that the status of the Olation Server is now marked Running.(highlighted below)



Click Close.