//' Connect to SMS Provider
                SmsNamedValuesDictionary namedValues = new SmsNamedValuesDictionary();
                WqlConnectionManager connection = new WqlConnectionManager(namedValues);
                connection.Connect(serverName);

System.IO.FileNotFoundException: 'Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.'

public static List<CollectionSccmCM> GetCMDeviceCollections(string hostname, string siteCode, string siteServer= null){
        List<CollectionSccmCM> collectionList = new List<CollectionSccmCM>();
            string Namespace;
            if(string.IsNullOrEmpty(siteServer)){
                Namespace = @"Root\SMS\Site_" + siteCode;
            } else {
                Namespace = (@"\\" + siteServer + @"\root\SMS\Site_" + siteCode);
            ManagementScope scope = new ManagementScope(Namespace);
            scope.Connect();
            ObjectQuery query = new ObjectQuery(String.Format("SELECT SMS_Collection.Name, SMS_Collection.CollectionID, SMS_Collection.CollectionType FROM SMS_FullCollectionMembership, SMS_Collection where name = '{0}' and SMS_FullCollectionMembership.CollectionID = SMS_Collection.CollectionID", hostname));
            ManagementObjectSearcher searcher = new ManagementObjectSearcher(scope, query);
            ManagementObjectCollection queryCollection = searcher.Get();
            if (queryCollection != null)
                foreach (ManagementObject obj in queryCollection)
                    CollectionSccmCM coll = new CollectionSccmCM()
                            Name = obj["Name"].ToString(),
                            CollectionID = obj["CollectionID"].ToString()
                        collectionList.Add(coll);
        catch (ManagementException ex)
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows)){
                EventService.WriteEventLog(String.Format("Unathorized access exception thrown: {0}", ex.Message), EventLogEntryType.Error);
        catch (Exception ex)
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows)){
                EventService.WriteEventLog(String.Format("Unhandled expection thrown: {0}", ex.Message), EventLogEntryType.Error);