The possible issues are the connectionstring that you're passing to connect to the server. The error would be thrown depending on any possible issues below,
- First thing is to make sure that you're passing the correct name for the SQL server or the database. If not, please correct it.
- Use the username and password that you used while creating the database.
- You should consider understanding that the connectionString must have all of the required authentication data before enabling your application to use it. So, if you used Windows authenticaion create a string for that, otherwise if you used Database authentication then use the settings for it; username password combination.
These issues must be resolved in order to connect your database to your application. The problem generally is just because of the username/password or the authenticaion mode problem. For more on these strings, please visit:
http://connectionstrings.com[
^].