Try M29 without check sum first

Author: luc-github

esp3d/config.h

@@ -19,7 +19,7 @@
 */
 
 //version and sources location
-#define FW_VERSION "2.1.1.b5"
+#define FW_VERSION "2.1.1.b6"
 #define REPOSITORY "https://github.com/luc-github/ESP3D"
 
 //Customize ESP3D ////////////////////////////////////////////////////////////////////////

esp3d/syncwebserver.cpp

@@ -1230,10 +1230,10 @@ void SDFile_serial_upload()
                 if (CONFIG::GetFirmwareTarget() == SMOOTHIEWARE)resetcmd = "N0 M110";
                 lineNb=1;
                 //close any ongoing upload and get current line number
-                if(!sendLine2Serial (command,1, &lineNb)){
+                if(!sendLine2Serial (command,-1, &lineNb)){
                     //it can failed for repetier
                     if ( ( CONFIG::GetFirmwareTarget() == REPETIER4DV) || (CONFIG::GetFirmwareTarget() == REPETIER) ) {
-                        if(!sendLine2Serial (command,-1, NULL)){
+                        if(!sendLine2Serial (command,1, NULL)){
                             log_esp3d("Upload start failed");
                             web_interface->_upload_status= UPLOAD_STATUS_FAILED;
                             pushError(ESP_ERROR_START_UPLOAD, "Upload rejected");