diff --git a/ios/Classes/SwiftAgoraRtmPlugin.swift b/ios/Classes/SwiftAgoraRtmPlugin.swift
index 80b819f..d442671 100644
--- a/ios/Classes/SwiftAgoraRtmPlugin.swift
+++ b/ios/Classes/SwiftAgoraRtmPlugin.swift
@@ -12,10 +12,10 @@ import AgoraRtmKit
 public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
     var registrar: FlutterPluginRegistrar!
     var methodChannel: FlutterMethodChannel!
-    
+
     var nextClientIndex: Int = 0
     var clients: [Int: RTMClient] = [:]
-    
+
     public static func register(with registrar: FlutterPluginRegistrar) {
         let channel = FlutterMethodChannel(name: "io.agora.rtm", binaryMessenger: registrar.messenger())
         let instance = SwiftAgoraRtmPlugin()
@@ -23,12 +23,12 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
         instance.registrar = registrar
         registrar.addMethodCallDelegate(instance, channel: channel)
     }
-    
+
     public func detachFromEngine(for registrar: FlutterPluginRegistrar) {
         methodChannel.setMethodCallHandler(nil)
         clients.removeAll()
     }
-    
+
     public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
         let methodName = call.method
         guard let callArguments = call.arguments as? [String: Any] else {
@@ -49,35 +49,59 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
             result(FlutterMethodNotImplemented)
         }
     }
-    
+
     func handleCallManagerMethod(_ methodName: String?, _ params: [String: Any?]?, _ result: @escaping FlutterResult) {
         if let clientIndex = params?["clientIndex"] as? Int, let agoraClient = clients[clientIndex], let callManager = agoraClient.call?.manager {
             let args = params?["args"] as? [String: Any?]
+            if (agoraClient.call == nil) {
+                result(["errorCode": -1])
+                return
+            }
             switch methodName {
             case "createLocalInvitation":
                 let calleeId = args?["calleeId"] as? String
+                if (calleeId == nil) {
+                    result(["errorCode": -1])
+                    return
+                }
                 let localInvitation = AgoraRtmLocalInvitation(calleeId: calleeId!)
                 agoraClient.call!.localInvitations[localInvitation.hash] = localInvitation
                 result(["errorCode": 0, "result": localInvitation.toJson()])
             case "sendLocalInvitation":
                 let localInvitation = (args?["localInvitation"] as? [String: Any?])?.toLocalInvitation(agoraClient.call!)
+                if (localInvitation == nil) {
+                    result(["errorCode": -1])
+                    return
+                }
                 callManager.send(localInvitation!) {
                     result(["errorCode": $0.rawValue])
                 }
             case "acceptRemoteInvitation":
                 let remoteInvitation = (args?["remoteInvitation"] as? [String: Any?])?.toRemoteInvitation(agoraClient.call!)
+                if (remoteInvitation == nil) {
+                    result(["errorCode": -1])
+                    return
+                }
                 callManager.accept(remoteInvitation!) {
                     agoraClient.call!.remoteInvitations.removeValue(forKey: remoteInvitation!.hash)
                     result(["errorCode": $0.rawValue])
                 }
             case "refuseRemoteInvitation":
                 let remoteInvitation = (args?["remoteInvitation"] as? [String: Any?])?.toRemoteInvitation(agoraClient.call!)
+                if (remoteInvitation == nil) {
+                    result(["errorCode": -1])
+                    return
+                }
                 callManager.refuse(remoteInvitation!) {
                     agoraClient.call!.remoteInvitations.removeValue(forKey: remoteInvitation!.hash)
                     result(["errorCode": $0.rawValue])
                 }
             case "cancelLocalInvitation":
                 let localInvitation = (args?["localInvitation"] as? [String: Any?])?.toLocalInvitation(agoraClient.call!)
+                if (localInvitation == nil) {
+                    result(["errorCode": -1])
+                    return
+                }
                 callManager.cancel(localInvitation!) {
                     agoraClient.call!.localInvitations.removeValue(forKey: localInvitation!.hash)
                     result(["errorCode": $0.rawValue])
@@ -87,7 +111,7 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
             }
         }
     }
-    
+
     func handleStaticMethod(_ methodName: String?, _ params: [String: Any?]?, _ result: @escaping FlutterResult) {
         switch methodName {
         case "createInstance":
@@ -112,7 +136,7 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
             result(FlutterMethodNotImplemented)
         }
     }
-    
+
     func handleClientMethod(_ methodName: String?, _ params: [String: Any?]?, _ result: @escaping FlutterResult) {
         if let clientIndex = params?["clientIndex"] as? Int, let agoraClient = clients[clientIndex], let client = agoraClient.client {
             let args = params?["args"] as? [String: Any?]
@@ -123,6 +147,10 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
             case "login":
                 let token = args?["token"] as? String
                 let userId = args?["userId"] as? String
+                if userId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.login(byToken: token, user: userId!) {
                     result(["errorCode": $0.rawValue])
                 }
@@ -134,17 +162,29 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
                 let peerId = args?["peerId"] as? String
                 let message = args?["message"] as? [String: Any?] ?? [:]
                 let options = args?["options"] as? [String: Any?] ?? [:]
+                if peerId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.send(message.toRtmMessage(), toPeer: peerId!, sendMessageOptions: options.toSendMessageOptions()) {
                     result(["errorCode": $0.rawValue])
                 }
             case "createChannel":
                 let channelId = args?["channelId"] as? String
+                if channelId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 let agoraRtmChannel = RTMChannel(clientIndex, channelId!, registrar.messenger())
                 let channel = client.createChannel(withId: channelId!, delegate: agoraRtmChannel)
                 agoraClient.channels[channelId!] = channel
                 result(["errorCode": 0])
             case "queryPeersOnlineStatus":
                 let peerIds = args?["peerIds"] as? [String]
+                if peerIds == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.queryPeersOnlineStatus(peerIds!) {
                     result(["errorCode": $1.rawValue, "result": $0?.reduce(into: [String: Int]()) {
                         $0[$1.peerId] = $1.state.rawValue
@@ -152,21 +192,37 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
                 }
             case "subscribePeersOnlineStatus":
                 let peerIds = args?["peerIds"] as? [String]
+                if peerIds == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.subscribePeersOnlineStatus(peerIds!) {
                     result(["errorCode": $0.rawValue])
                 }
             case "unsubscribePeersOnlineStatus":
                 let peerIds = args?["peerIds"] as? [String]
+                if peerIds == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.unsubscribePeersOnlineStatus(peerIds!) {
                     result(["errorCode": $0.rawValue])
                 }
             case "queryPeersBySubscriptionOption":
                 let option = args?["option"] as? Int
+                if option == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.queryPeers(bySubscriptionOption: AgoraRtmPeerSubscriptionOptions(rawValue: option!)!) {
                     result(["errorCode": $1.rawValue, "result": $0])
                 }
             case "renewToken":
                 let token = args?["token"] as? String
+                if token == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.renewToken(token!) {
                     result(["errorCode": $1.rawValue, "result": $0])
                 }
@@ -182,6 +238,10 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
                 }
             case "deleteLocalUserAttributesByKeys":
                 let keys = args?["keys"] as? [String]
+                if keys == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.deleteLocalUserAttributes(byKeys: keys!) {
                     result(["errorCode": $0.rawValue])
                 }
@@ -191,12 +251,20 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
                 }
             case "getUserAttributes":
                 let userId = args?["userId"] as? String
+                if userId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.getUserAllAttributes(userId!) {
                     result(["errorCode": $2.rawValue, "result": $0?.toJson(), "userId": $1])
                 }
             case "getUserAttributesByKeys":
                 let userId = args?["userId"] as? String
                 let keys = args?["keys"] as? [String]
+                if userId == nil || keys == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.getUserAttributes(userId!, byKeys: keys!) {
                     result(["errorCode": $2.rawValue, "result": $0?.toJson(), "userId": $1])
                 }
@@ -204,6 +272,10 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
                 let channelId = args?["channelId"] as? String
                 let attributes = args?["attributes"] as? [[String: Any?]] ?? []
                 let options = args?["options"] as? [String: Any?] ?? [:]
+                if channelId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.setChannel(channelId!, attributes: attributes.toRtmChannelAttributeList(), options: options.toChannelAttributeOptions()) {
                     result(["errorCode": $0.rawValue])
                 }
@@ -211,6 +283,10 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
                 let channelId = args?["channelId"] as? String
                 let attributes = args?["attributes"] as? [[String: Any?]] ?? []
                 let options = args?["options"] as? [String: Any?] ?? [:]
+                if channelId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.addOrUpdateChannel(channelId!, attributes: attributes.toRtmChannelAttributeList(), options: options.toChannelAttributeOptions()) {
                     result(["errorCode": $0.rawValue])
                 }
@@ -218,45 +294,81 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
                 let channelId = args?["channelId"] as? String
                 let keys = args?["keys"] as? [String]
                 let options = args?["options"] as? [String: Any?] ?? [:]
+                if channelId == nil || keys == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.deleteChannel(channelId!, attributesByKeys: keys!, options: options.toChannelAttributeOptions()) {
                     result(["errorCode": $0.rawValue])
                 }
             case "clearChannelAttributes":
                 let channelId = args?["channelId"] as? String
                 let options = args?["options"] as? [String: Any?] ?? [:]
+                if channelId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.clearChannel(channelId!, options: options.toChannelAttributeOptions()) {
                     result(["errorCode": $0.rawValue])
                 }
             case "getChannelAttributes":
                 let channelId = args?["channelId"] as? String
+                if channelId == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.getChannelAllAttributes(channelId!) {
                     result(["errorCode": $1.rawValue, "result": $0?.toJson()])
                 }
             case "getChannelAttributesByKeys":
                 let channelId = args?["channelId"] as? String
                 let keys = args?["keys"] as? [String]
+                if channelId == nil || keys == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.getChannelAttributes(channelId!, byKeys: keys!) {
                     result(["errorCode": $1.rawValue, "result": $0?.toJson()])
                 }
             case "getChannelMemberCount":
                 let channelIds = args?["channelIds"] as? [String]
+                if channelIds == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 client.getChannelMemberCount(channelIds!) {
                     result(["errorCode": $1.rawValue, "result": $0?.toJson()])
                 }
             case "setParameters":
                 let parameters = args?["parameters"] as? String
+                if parameters == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 let errorCode = client.setParameters(parameters!)
                 result(["errorCode": errorCode])
             case "setLogFile":
                 let filePath = args?["filePath"] as? String
+                if filePath == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 let errorCode = client.setLogFile(filePath!)
                 result(["errorCode": errorCode])
             case "setLogFilter":
                 let filter = args?["filter"] as? Int
+                if filter == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 let errorCode = client.setLogFilters(AgoraRtmLogFilter(rawValue: filter!)!)
                 result(["errorCode": errorCode])
             case "setLogFileSize":
                 let fileSizeInKBytes = args?["fileSizeInKBytes"] as? Int32
+                if fileSizeInKBytes == nil {
+                    result(["errorCode": -1])
+                    return
+                }
                 let errorCode = client.setLogFileSize(fileSizeInKBytes!)
                 result(["errorCode": errorCode])
             default:
@@ -264,7 +376,7 @@ public class SwiftAgoraRtmPlugin: NSObject, FlutterPlugin {
             }
         }
     }
-    
+
     func handleChannelMethod(_ methodName: String?, _ params: [String: Any?]?, _ result: @escaping FlutterResult) {
         if let clientIndex = params?["clientIndex"] as? Int, let channelId = params?["channelId"] as? String, let agoraClient = clients[clientIndex], let channel = agoraClient.channels[channelId] {
             let args = params?["args"] as? [String: Any?]