diff --git a/requests_copy.go b/requests_copy.go
index 102466c..e0728d6 100644
--- a/requests_copy.go
+++ b/requests_copy.go
@@ -370,9 +370,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 
 		fh, err := os.Open(cia.SrcFilePath)
 		if err != nil {
-			// errCh <- fmt.Errorf("error: copySrcSubProcFunc: failed to open file: %v, %v", SrcFilePath, err)
-			log.Fatalf("error: copySrcSubProcFunc: failed to open file: %v\n", err)
-			return nil
+			er := fmt.Errorf("error: copySrcSubProcFunc: failed to open file: %v", err)
+			proc.errorKernel.errSend(proc, Message{}, er)
+			return er
 		}
 		defer fh.Close()
 
@@ -389,7 +389,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 				var csa copySubData
 				err := cbor.Unmarshal(message.Data, &csa)
 				if err != nil {
-					log.Fatalf("error: copySrcSubHandler: cbor unmarshal of csa failed: %v\n", err)
+					er := fmt.Errorf("error: copySrcSubHandler: cbor unmarshal of csa failed: %v", err)
+					proc.errorKernel.errSend(proc, message, er)
+					return er
 				}
 
 				switch csa.CopyStatus {
@@ -401,7 +403,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 					b := make([]byte, cia.SplitChunkSize)
 					n, err := fh.Read(b)
 					if err != nil && err != io.EOF {
-						log.Printf("error: copySrcSubHandler: failed to read chuck from file: %v\n", err)
+						er := fmt.Errorf("error: copySrcSubHandler: failed to read chunk from file: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 					if err == io.EOF {
 						status = copySrcDone
@@ -426,7 +430,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 
 					csaSerialized, err := cbor.Marshal(csa)
 					if err != nil {
-						log.Fatalf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v\n", err)
+						er := fmt.Errorf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 
 					// We want to send a message back to src that we are ready to start.
@@ -444,7 +450,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 
 					sam, err := newSubjectAndMessage(msg)
 					if err != nil {
-						log.Fatalf("copyDstProcSubFunc: newSubjectAndMessage failed: %v\n", err)
+						er := fmt.Errorf("copyDstProcSubFunc: newSubjectAndMessage failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 
 					proc.toRingbufferCh <- []subjectAndMessage{sam}
@@ -483,7 +491,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 
 					csaSerialized, err := cbor.Marshal(csa)
 					if err != nil {
-						log.Fatalf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v\n", err)
+						er := fmt.Errorf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 
 					// We want to send a message back to src that we are ready to start.
@@ -501,7 +511,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 
 					sam, err := newSubjectAndMessage(msg)
 					if err != nil {
-						log.Fatalf("copyDstProcSubFunc: newSubjectAndMessage failed: %v\n", err)
+						er := fmt.Errorf("copyDstProcSubFunc: newSubjectAndMessage failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 
 					proc.toRingbufferCh <- []subjectAndMessage{sam}
@@ -513,7 +525,9 @@ func copySrcSubProcFunc(proc process, cia copyInitialData, cancel context.Cancel
 
 				default:
 					// TODO: Any error logic here ?
-					log.Fatalf("error: copySrcSubProcFunc: not valid copyStatus, exiting: %v\n", csa.CopyStatus)
+					er := fmt.Errorf("error: copySrcSubProcFunc: not valid copyStatus, exiting: %v", csa.CopyStatus)
+					proc.errorKernel.errSend(proc, message, er)
+					return er
 				}
 			}
 		}
@@ -535,7 +549,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 		csaSerialized, err := cbor.Marshal(csa)
 		if err != nil {
-			log.Fatalf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v\n", err)
+			er := fmt.Errorf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v", err)
+			proc.errorKernel.errSend(proc, message, er)
+			return er
 		}
 
 		// We want to send a message back to src that we are ready to start.
@@ -554,7 +570,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 			sam, err := newSubjectAndMessage(msg)
 			if err != nil {
-				log.Fatalf("copyDstProcSubFunc: newSubjectAndMessage failed: %v\n", err)
+				er := fmt.Errorf("copyDstProcSubFunc: newSubjectAndMessage failed: %v", err)
+				proc.errorKernel.errSend(proc, message, er)
+				return er
 			}
 
 			proc.toRingbufferCh <- []subjectAndMessage{sam}
@@ -574,7 +592,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 				var csa copySubData
 				err := cbor.Unmarshal(message.Data, &csa)
 				if err != nil {
-					log.Fatalf("error: copySrcSubHandler: cbor unmarshal of csa failed: %v\n", err)
+					er := fmt.Errorf("error: copySrcSubHandler: cbor unmarshal of csa failed: %v", err)
+					proc.errorKernel.errSend(proc, message, er)
+					return er
 				}
 
 				// Check if the hash matches. If it fails we set the status so we can
@@ -593,20 +613,29 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 					// Write the data chunk to disk ?
 					// fmt.Printf("\n * Received data: %s\n\n", csa.CopyData)
 
-					func() {
+					err := func() error {
 						filePath := filepath.Join(tmpFolder, strconv.Itoa(csa.ChunkNumber)+"."+cia.UUID)
 						fh, err := os.OpenFile(filePath, os.O_TRUNC|os.O_RDWR|os.O_CREATE|os.O_SYNC, 0600)
 						if err != nil {
-							log.Fatalf("error: copyDstSubProcFunc: open file failed: %v\n", err)
+							er := fmt.Errorf("error: copyDstSubProcFunc: open file failed: %v", err)
+							return er
 						}
 						defer fh.Close()
 
 						_, err = fh.Write(csa.CopyData)
 						if err != nil {
-							log.Fatalf("error: copyDstSubProcFunc: open file failed: %v\n", err)
+							er := fmt.Errorf("error: copyDstSubProcFunc: open file failed: %v", err)
+							return er
 						}
+
+						return nil
 					}()
 
+					if err != nil {
+						proc.errorKernel.errSend(proc, message, err)
+						return err
+					}
+
 					// Prepare and send a ready message to src for the next chunk.
 					csa := copySubData{
 						CopyStatus: copyReady,
@@ -614,7 +643,8 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 					csaSer, err := cbor.Marshal(csa)
 					if err != nil {
-						log.Fatalf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v\n", err)
+						er := fmt.Errorf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
 					}
 
 					// fmt.Printf("\n\n\n ************** DEBUG: copyDstHandler sub process sending copyReady to:%v\n ", message.FromNode)
@@ -631,7 +661,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 					sam, err := newSubjectAndMessage(msg)
 					if err != nil {
-						log.Fatalf("copyDstProcSubFunc: newSubjectAndMessage failed: %v\n", err)
+						er := fmt.Errorf("copyDstProcSubFunc: newSubjectAndMessage failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 
 					proc.toRingbufferCh <- []subjectAndMessage{sam}
@@ -642,7 +674,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 					// resend of the last message.
 					csaSer, err := cbor.Marshal(csa)
 					if err != nil {
-						log.Fatalf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v\n", err)
+						er := fmt.Errorf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 
 					msg := Message{
@@ -656,13 +690,15 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 					sam, err := newSubjectAndMessage(msg)
 					if err != nil {
-						log.Fatalf("copyDstProcSubFunc: newSubjectAndMessage failed: %v\n", err)
+						er := fmt.Errorf("copyDstProcSubFunc: newSubjectAndMessage failed: %v", err)
+						proc.errorKernel.errSend(proc, message, er)
+						return er
 					}
 
 					proc.toRingbufferCh <- []subjectAndMessage{sam}
 
 				case copySrcDone:
-					func() {
+					err := func() error {
 
 						// Open the main file that chunks files will be written into.
 						filePath := filepath.Join(cia.DstDir, cia.DstFile)
@@ -673,7 +709,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 						mainfh, err := os.OpenFile(filePath, os.O_TRUNC|os.O_RDWR|os.O_CREATE|os.O_SYNC, cia.FileMode)
 						if err != nil {
-							log.Fatalf("error: copyDstSubProcFunc: open file failed: %v\n", err)
+							er := fmt.Errorf("error: copyDstSubProcFunc: open file failed: %v", err)
+							proc.errorKernel.errSend(proc, message, er)
+							return er
 						}
 						defer mainfh.Close()
 
@@ -721,9 +759,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 						fmt.Printf(" * sorted slice: %v\n", files)
 
 						if err != nil {
-							log.Printf("error: copyDstSubProcFunc: creation of slice of chunk paths failed: %v\n", err)
-
-							return
+							er := fmt.Errorf("error: copyDstSubProcFunc: creation of slice of chunk paths failed: %v", err)
+							proc.errorKernel.errSend(proc, message, er)
+							return er
 						}
 
 						err = func() error {
@@ -761,7 +799,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 						os.Remove(backupOriginalFileName)
 						err = os.RemoveAll(tmpFolder)
 						if err != nil {
-							log.Fatalf("error: copyDstSubProcFunc: remove temp dir failed: %v\n", err)
+							er := fmt.Errorf("error: copyDstSubProcFunc: remove temp dir failed: %v", err)
+							proc.errorKernel.errSend(proc, message, er)
+							return er
 						}
 
 						log.Printf("info: copy: successfully wrote all split chunk files into file=%v\n", filePath)
@@ -774,7 +814,9 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 							csaSerialized, err := cbor.Marshal(csa)
 							if err != nil {
-								log.Fatalf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v\n", err)
+								er := fmt.Errorf("error: copyDstSubProcFunc: cbor marshal of csa failed: %v", err)
+								proc.errorKernel.errSend(proc, message, er)
+								return er
 							}
 
 							// We want to send a message back to src that we are ready to start.
@@ -792,14 +834,22 @@ func copyDstSubProcFunc(proc process, cia copyInitialData, message Message, canc
 
 							sam, err := newSubjectAndMessage(msg)
 							if err != nil {
-								log.Fatalf("copyDstProcSubFunc: newSubjectAndMessage failed: %v\n", err)
+								er := fmt.Errorf("copyDstProcSubFunc: newSubjectAndMessage failed: %v", err)
+								proc.errorKernel.errSend(proc, message, er)
+								return er
 							}
 
 							proc.toRingbufferCh <- []subjectAndMessage{sam}
 						}
 
 						cancel()
+
+						return nil
 					}()
+
+					if err != nil {
+						return err
+					}
 				}
 			}
 		}