you don't need to check for ConnectionState
If the connection cannot be opened an exception is throw
Maybe this check is causing your issue
protected static bool TestaIntegracaoErpMigplus()
{
bool ret = true;
try
{
string connectionStringMigplus = WebConfigurationManager.ConnectionStrings["ConnectionStringMigplus"].ConnectionString;
using (SqlConnection Conn = new SqlConnection(connectionStringMigplus))
{
Conn.Open();
}
}
catch (Exception)
{
ret = false;
}
return ret;
}
-------------UPDATE------------------
Try to lower the connection timeout in the connection string:
<add name="ConnectionStringMigplus" connectionString="Data Source=999.99.999.99;Initial Catalog=xxx;user=xxx;pwd=xxx;Connection Timeout=5" providerName="System.Data.SqlClient" />