diff --git a/NearDrop.xcodeproj/project.pbxproj b/NearDrop.xcodeproj/project.pbxproj
index 4c6c1ab..689ca50 100644
--- a/NearDrop.xcodeproj/project.pbxproj
+++ b/NearDrop.xcodeproj/project.pbxproj
@@ -823,7 +823,7 @@
 				CODE_SIGN_ENTITLEMENTS = NearDrop/NearDrop.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 6;
+				CURRENT_PROJECT_VERSION = 7;
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_KEY_LSApplicationCategoryType = "public.app-category.utilities";
 				INFOPLIST_KEY_LSUIElement = YES;
@@ -835,7 +835,7 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = 11.0;
-				MARKETING_VERSION = 2.0.2;
+				MARKETING_VERSION = 2.0.3;
 				PRODUCT_BUNDLE_IDENTIFIER = me.grishka.NearDrop;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;
@@ -855,7 +855,7 @@
 				CODE_SIGN_ENTITLEMENTS = NearDrop/NearDrop.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
-				CURRENT_PROJECT_VERSION = 6;
+				CURRENT_PROJECT_VERSION = 7;
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_KEY_LSApplicationCategoryType = "public.app-category.utilities";
 				INFOPLIST_KEY_LSUIElement = YES;
@@ -867,7 +867,7 @@
 					"@executable_path/../Frameworks",
 				);
 				MACOSX_DEPLOYMENT_TARGET = 11.0;
-				MARKETING_VERSION = 2.0.2;
+				MARKETING_VERSION = 2.0.3;
 				PRODUCT_BUNDLE_IDENTIFIER = me.grishka.NearDrop;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;
diff --git a/NearDrop.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved b/NearDrop.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved
index 71bb841..12467f6 100644
--- a/NearDrop.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved
+++ b/NearDrop.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved
@@ -1,5 +1,4 @@
 {
-  "originHash" : "5bbb4a57a61db67d6ce8adc203fbc456a84ce246fff6c01807617c5de6a47adc",
   "pins" : [
     {
       "identity" : "asn1",
@@ -38,5 +37,5 @@
       }
     }
   ],
-  "version" : 3
+  "version" : 2
 }
diff --git a/NearbyShare/InboundNearbyConnection.swift b/NearbyShare/InboundNearbyConnection.swift
index 9fc317b..a56da79 100644
--- a/NearbyShare/InboundNearbyConnection.swift
+++ b/NearbyShare/InboundNearbyConnection.swift
@@ -129,7 +129,7 @@ class InboundNearbyConnection: NearbyConnection{
 	}
 	
 	private func processConnectionRequestFrame(_ frame:Location_Nearby_Connections_OfflineFrame) throws{
-		guard frame.hasV1 && frame.v1.hasConnectionRequest && frame.v1.connectionRequest.hasEndpointInfo else { throw NearbyError.requiredFieldMissing }
+		guard frame.hasV1 && frame.v1.hasConnectionRequest && frame.v1.connectionRequest.hasEndpointInfo else { throw NearbyError.requiredFieldMissing("connectionRequest.endpointInfo") }
 		guard case .connectionRequest = frame.v1.type else { throw NearbyError.protocolError("Unexpected frame type \(frame.v1.type)") }
 		let endpointInfo=frame.v1.connectionRequest.endpointInfo
 		guard endpointInfo.count>17 else { throw NearbyError.protocolError("Endpoint info too short") }
@@ -142,7 +142,7 @@ class InboundNearbyConnection: NearbyConnection{
 	}
 	
 	private func processUkey2ClientInit(_ msg:Securegcm_Ukey2Message) throws{
-		guard msg.hasMessageType, msg.hasMessageData else { throw NearbyError.requiredFieldMissing }
+		guard msg.hasMessageType, msg.hasMessageData else { throw NearbyError.requiredFieldMissing("clientInit ukey2message.type|data") }
 		guard case .clientInit = msg.messageType else{
 			sendUkey2Alert(type: .badMessageType)
 			throw NearbyError.ukey2
@@ -206,7 +206,7 @@ class InboundNearbyConnection: NearbyConnection{
 	}
 	
 	private func processUkey2ClientFinish(_ msg:Securegcm_Ukey2Message, raw:Data) throws{
-		guard msg.hasMessageType, msg.hasMessageData else { throw NearbyError.requiredFieldMissing }
+		guard msg.hasMessageType, msg.hasMessageData else { throw NearbyError.requiredFieldMissing("clientFinish ukey2message.type|data") }
 		guard case .clientFinish = msg.messageType else { throw NearbyError.ukey2 }
 		
 		var sha=SHA512()
@@ -214,7 +214,7 @@ class InboundNearbyConnection: NearbyConnection{
 		guard cipherCommitment==Data(sha.finalize()) else { throw NearbyError.ukey2 }
 		
 		let clientFinish=try Securegcm_Ukey2ClientFinished(serializedData: msg.messageData)
-		guard clientFinish.hasPublicKey else {throw NearbyError.requiredFieldMissing }
+		guard clientFinish.hasPublicKey else {throw NearbyError.requiredFieldMissing("ukey2clientFinish.publicKey") }
 		let clientKey=try Securemessage_GenericPublicKey(serializedData: clientFinish.publicKey)
 		
 		try finalizeKeyExchange(peerKey: clientKey)
@@ -223,7 +223,7 @@ class InboundNearbyConnection: NearbyConnection{
 	}
 	
 	private func processConnectionResponseFrame(_ frame:Location_Nearby_Connections_OfflineFrame) throws{
-		guard frame.hasV1, frame.v1.hasType else { throw NearbyError.requiredFieldMissing }
+		guard frame.hasV1, frame.v1.hasType else { throw NearbyError.requiredFieldMissing("offlineFrame.v1.type") }
 		if case .connectionResponse = frame.v1.type {
 			var resp=Location_Nearby_Connections_OfflineFrame()
 			resp.version = .v1
@@ -254,7 +254,7 @@ class InboundNearbyConnection: NearbyConnection{
 	}
 	
 	private func processPairedKeyEncryptionFrame(_ frame:Sharing_Nearby_Frame) throws{
-		guard frame.hasV1, frame.v1.hasPairedKeyEncryption else { throw NearbyError.requiredFieldMissing }
+		guard frame.hasV1, frame.v1.hasPairedKeyEncryption else { throw NearbyError.requiredFieldMissing("shareNearbyFrame.v1.pairedKeyEncryption") }
 		var pairedResult=Sharing_Nearby_Frame()
 		pairedResult.version = .v1
 		pairedResult.v1=Sharing_Nearby_V1Frame()
@@ -266,12 +266,12 @@ class InboundNearbyConnection: NearbyConnection{
 	}
 	
 	private func processPairedKeyResultFrame(_ frame:Sharing_Nearby_Frame) throws{
-		guard frame.hasV1, frame.v1.hasPairedKeyResult else { throw NearbyError.requiredFieldMissing }
+		guard frame.hasV1, frame.v1.hasPairedKeyResult else { throw NearbyError.requiredFieldMissing("shareNearbyFrame.v1.pairedKeyResult") }
 		currentState = .receivedPairedKeyResult
 	}
 	
 	private func processIntroductionFrame(_ frame:Sharing_Nearby_Frame) throws{
-		guard frame.hasV1, frame.v1.hasIntroduction else { throw NearbyError.requiredFieldMissing }
+		guard frame.hasV1, frame.v1.hasIntroduction else { throw NearbyError.requiredFieldMissing("shareNearbyFrame.v1.introduction") }
 		currentState = .waitingForUserConsent
 		if frame.v1.introduction.fileMetadata.count>0 && frame.v1.introduction.textMetadata.isEmpty{
 			let downloadsDirectory=(try FileManager.default.url(for: .downloadsDirectory, in: .userDomainMask, appropriateFor: nil, create: true)).resolvingSymlinksInPath()
diff --git a/NearbyShare/NearbyConnection.swift b/NearbyShare/NearbyConnection.swift
index 697d33b..8cc206f 100644
--- a/NearbyShare/NearbyConnection.swift
+++ b/NearbyShare/NearbyConnection.swift
@@ -232,7 +232,7 @@ class NearbyConnection{
 	}
 	
 	internal func decryptAndProcessReceivedSecureMessage(_ smsg:Securemessage_SecureMessage) throws{
-		guard smsg.hasSignature, smsg.hasHeaderAndBody else { throw NearbyError.requiredFieldMissing }
+		guard smsg.hasSignature, smsg.hasHeaderAndBody else { throw NearbyError.requiredFieldMissing("secureMessage.signature|headerAndBody") }
 		let hmac=Data(HMAC<SHA256>.authenticationCode(for: smsg.headerAndBody, using: recvHmacKey!))
 		guard hmac==smsg.signature else { throw NearbyError.protocolError("hmac!=signature") }
 		let headerAndBody=try Securemessage_HeaderAndBody(serializedData: smsg.headerAndBody)
@@ -254,19 +254,18 @@ class NearbyConnection{
 		})
 		decryptedData=decryptedData.prefix(decryptedLength)
 		let d2dMsg=try Securegcm_DeviceToDeviceMessage(serializedData: decryptedData)
-		guard d2dMsg.hasMessage, d2dMsg.hasSequenceNumber else { throw NearbyError.requiredFieldMissing }
+		guard d2dMsg.hasMessage, d2dMsg.hasSequenceNumber else { throw NearbyError.requiredFieldMissing("d2dMessage.message|sequenceNumber") }
 		clientSeq+=1
 		guard d2dMsg.sequenceNumber==clientSeq else { throw NearbyError.protocolError("Wrong sequence number. Expected \(clientSeq), got \(d2dMsg.sequenceNumber)") }
 		let offlineFrame=try Location_Nearby_Connections_OfflineFrame(serializedData: d2dMsg.message)
-		guard offlineFrame.hasV1, offlineFrame.v1.hasType else { throw NearbyError.requiredFieldMissing }
 		
-		if case .payloadTransfer = offlineFrame.v1.type {
-			guard offlineFrame.v1.hasPayloadTransfer else { throw NearbyError.requiredFieldMissing }
+		if offlineFrame.hasV1 && offlineFrame.v1.hasType, case .payloadTransfer = offlineFrame.v1.type {
+			guard offlineFrame.v1.hasPayloadTransfer else { throw NearbyError.requiredFieldMissing("offlineFrame.v1.payloadTransfer") }
 			let payloadTransfer=offlineFrame.v1.payloadTransfer
 			let header=payloadTransfer.payloadHeader;
 			let chunk=payloadTransfer.payloadChunk;
-			guard header.hasType, header.hasID else { throw NearbyError.requiredFieldMissing }
-			guard payloadTransfer.hasPayloadChunk, chunk.hasOffset, chunk.hasFlags else { throw NearbyError.requiredFieldMissing }
+			guard header.hasType, header.hasID else { throw NearbyError.requiredFieldMissing("payloadHeader.type|id") }
+			guard payloadTransfer.hasPayloadChunk, chunk.hasOffset, chunk.hasFlags else { throw NearbyError.requiredFieldMissing("payloadTransfer.payloadChunk|offset|flags") }
 			if case .bytes = header.type{
 				let payloadID=header.id
 				if header.totalSize>InboundNearbyConnection.SANE_FRAME_LENGTH{
@@ -294,7 +293,7 @@ class NearbyConnection{
 			}else if case .file = header.type{
 				try processFileChunk(frame: payloadTransfer)
 			}
-		}else if case .keepAlive = offlineFrame.v1.type{
+		}else if offlineFrame.hasV1 && offlineFrame.v1.hasType, case .keepAlive = offlineFrame.v1.type{
 			#if DEBUG
 			print("Sent keep-alive")
 			#endif
@@ -321,7 +320,7 @@ class NearbyConnection{
 	}
 	
 	internal func finalizeKeyExchange(peerKey:Securemessage_GenericPublicKey) throws{
-		guard peerKey.hasEcP256PublicKey else { throw NearbyError.requiredFieldMissing }
+		guard peerKey.hasEcP256PublicKey else { throw NearbyError.requiredFieldMissing("peerKey.ecP256PublicKey") }
 		
 		let domain=Domain.instance(curve: .EC256r1)
 		var clientX=peerKey.ecP256PublicKey.x
diff --git a/NearbyShare/NearbyConnectionManager.swift b/NearbyShare/NearbyConnectionManager.swift
index 2938115..2874ad0 100644
--- a/NearbyShare/NearbyConnectionManager.swift
+++ b/NearbyShare/NearbyConnectionManager.swift
@@ -51,7 +51,7 @@ public struct RemoteDeviceInfo{
 
 public enum NearbyError:Error{
 	case protocolError(_ message:String)
-	case requiredFieldMissing
+	case requiredFieldMissing(_ message:String)
 	case ukey2
 	case inputOutput(cause:Errno)
 	case canceled(reason:CancellationReason)
diff --git a/NearbyShare/OutboundNearbyConnection.swift b/NearbyShare/OutboundNearbyConnection.swift
index 3e9787b..76214c1 100644
--- a/NearbyShare/OutboundNearbyConnection.swift
+++ b/NearbyShare/OutboundNearbyConnection.swift
@@ -243,7 +243,7 @@ class OutboundNearbyConnection:NearbyConnection{
 	}
 	
 	private func processPairedKeyEncryption(frame:Sharing_Nearby_Frame) throws{
-		guard frame.hasV1, frame.v1.hasPairedKeyEncryption else { throw NearbyError.requiredFieldMissing }
+		guard frame.hasV1, frame.v1.hasPairedKeyEncryption else { throw NearbyError.requiredFieldMissing("sharingNearbyFrame.v1.pairedKeyEncryption") }
 		var pairedResult=Sharing_Nearby_Frame()
 		pairedResult.version = .v1
 		pairedResult.v1=Sharing_Nearby_V1Frame()
@@ -255,7 +255,7 @@ class OutboundNearbyConnection:NearbyConnection{
 	}
 	
 	private func processPairedKeyResult(frame:Sharing_Nearby_Frame) throws{
-		guard frame.hasV1, frame.v1.hasPairedKeyResult else { throw NearbyError.requiredFieldMissing }
+		guard frame.hasV1, frame.v1.hasPairedKeyResult else { throw NearbyError.requiredFieldMissing("sharingNearbyFrame.v1.pairedKeyResult") }
 		
 		var introduction=Sharing_Nearby_Frame()
 		introduction.version = .v1
@@ -308,7 +308,7 @@ class OutboundNearbyConnection:NearbyConnection{
 	}
 	
 	private func processConsent(frame:Sharing_Nearby_Frame) throws{
-		guard frame.version == .v1, frame.v1.type == .response else {throw NearbyError.requiredFieldMissing}
+		guard frame.version == .v1, frame.v1.type == .response else {throw NearbyError.requiredFieldMissing("sharingNearbyFrame.v1.type==response")}
 		switch frame.v1.connectionResponse.status{
 		case .accept:
 			currentState = .sendingFiles