"SQL Server does not exist or access denied" Error during Login

Overview

This article outlines the solution when Everest clients running on remote workstations are failing to login and getting the error:

"SQL Server does not exist or access denied". 

At the same time, a local client running on the Everest server is able to connect and login successfully without errors.

Solution

The above error is an MDAC (Microsoft Data Access Components) message that indicates that client workstations are unable to connect to the host running the SQL Server.

This error can occur if any of the following conditions are true:

• SQL Server Service is not running
• SQL Server Browser service is disabled
• SQL Server does not exist or unavailable
• Remote connection is disabled for SQL instance
• SQL Server Port has not been added to the firewall exception list
• The IP address of the instance is blocked

Follow these steps to isolate the root cause and resolve the issue:

1. SQL Server Service is not running

   Start by checking whether SQL Server is running.

   For this enter the “services.msc” command in the Run window (Windows logo + R).

   

2. Ensure that the SQL Server Browser service is enabled and running by opening the SQL Server Configuration Manager and selecting SQL Server Services on the left panel. Right-click on SQL Server Browser on the right pane and select Properties. Enable and start the service if necessary. It is recommended that you change the Start Mode to Automatic so that the service is started automatically each time the server is restarted.  
3. SQL Server instance is not available or does not exist

   Check the connection strings and make sure that you are trying to connect to the correct server and it is available on the network. Verify basic connectivity over IP address and check for any abnormalities:

   ping –a <SQL Server machine>, ping –a <SQL Server IP address>. Any connectivity issues should be resolved with your network administrator before proceeding.

4. Remote connection is not enabled for a SQL Server instance

   To check the remote connection is enabled or disabled, open SQL Server Management Studio -> Connect to SQL Server where it is installed using SQL Server Management Studio -> Go to SQL Server instance property and check to Allow remote connection to this server.

   

5. Port has not been added to the firewall exception list

   This error message can occur when SQL Server remote connection is enabled, but the port is blocked by the administrator for security purposes.

   SQL Server instance works on port 1433 (by default), so you need to check that the port exception is also added to the firewall.

   To check the port exception follow the below-mentioned steps:

   • Go to Control Panel -> Open Administrative Tool -> Select Windows firewall with Advanced Security.

     

   • From the left panel, click on the Inbound Rules, and from the right panel select New Rule…

     

   • In New Inbound Rule Wizard window, select Port and click on Next button.

     

   • In the next tab, enter ‘1433’ (or your custom configured port if not using the default port) in Specific local ports and click on Next button.

     

   • Under What action should be taken when a connection matches the specified condition? section, select Allow the connection option and click on Next.

     

   • Check Domain, Private, Public under which does this rule apply section? and click on Next.

     

   • Enter the Name and click on the Finish button.

     

6. The IP address of the SQL Server Instance is blocked by a Firewall

   To check SQL Server does not exist or access denied is occurring because of IP address, ping IP address on the command prompt like

   Ping 100.10.10.10 –t

   If you are getting a success response from the server then it means that network connectivity is established and that the IP address is not blocked, otherwise, you need to add a firewall exception (see point 4 above).

Testing

Carrying out the above steps should resolve the issue and Everest clients running on remote workstations should be able to successfully connect with users able to log in without any errors.

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