When user a 'Dynamics NAV 2013 and later (SQL Server)' data source in the Jet Excel Add-In, a non-admin user can receive the following error:
Complete text of error message is:
An unexpected error has occurred: The type initializer for 'System.Data.SqlClient.SqlConnection' threw an exception.
Non-admin user accounts need to be assigned to the "Impersonate a client after authentication" security policy role to allow the Jet Excel Add-In to access data directly from a SQL database.
Here are the steps that a LOCAL ADMINISTRATOR will need to follow to add the non-admin user to this role:
From the Windows Start menu, search for Administrative Tools and click the Control Panel app
Double-click Local Security Policy
Expand Local Policies, and then click User Rights Assignment
In the right pane, double-click Impersonate a client after authentication
In the Local Security Policy Setting dialog box, click Add User or Group
In the Select Users or Group dialog box, find the user account that you want to add, then click OK
Click OK on the Local Security Policy Setting dialog box
Reboot the system and try the steps to reproduce the problem