Issue : 
                                A Get/Change First Operation on Table coProcess failed Accessing SQL Data” error message when you log into Microsoft Dynamics GP after moving from one server to another

Solution :

Step 1 : Goto sql server management studio and open sql server
Step 2 : Expand databases
Step 3 : Expand Company Database
Step 4 : Expand security node in under company database
Step 5 : Expand users
Step 6 : Delete the user(Which user you trying to login GP)
Step 7 : Login GP using sa user
Step 8 : Goto Microsoft Dynamics GP--Tools--Setup--System--User Access
Step 9 : Select the deleted user and uncheck the company access
Step 10 : Again check the Company access
Step 11 : Select OK
Step 12 : Goto Microsoft Dynamics GP--Tools--Setup--System--User Security
Step 13: Select the user and assign the role

Now you can login GP using same user