diff --git a/cura/Settings/QualityAndUserProfilesModel.py b/cura/Settings/QualityAndUserProfilesModel.py
index f2728aff14..602f8768da 100644
--- a/cura/Settings/QualityAndUserProfilesModel.py
+++ b/cura/Settings/QualityAndUserProfilesModel.py
@@ -41,6 +41,9 @@ class QualityAndUserProfilesModel(ProfilesModel):
             new_extruder_stacks = []
             if active_extruder is not None:
                 new_extruder_stacks = [active_extruder]
+            else:
+                # if there is no active extruder, use the first one in the active extruder stacks
+                active_extruder = extruder_stacks[0]
             extruder_stacks = new_extruder_stacks + extruder_stacks
 
         # Fetch the list of useable qualities across all extruders.
diff --git a/cura/Settings/UserProfilesModel.py b/cura/Settings/UserProfilesModel.py
index 587e27f359..aa815ef4aa 100644
--- a/cura/Settings/UserProfilesModel.py
+++ b/cura/Settings/UserProfilesModel.py
@@ -41,6 +41,9 @@ class UserProfilesModel(ProfilesModel):
             new_extruder_stacks = []
             if active_extruder is not None:
                 new_extruder_stacks = [active_extruder]
+            else:
+                # if there is no active extruder, use the first one in the active extruder stacks
+                active_extruder = extruder_stacks[0]
             extruder_stacks = new_extruder_stacks + extruder_stacks
 
         # Fetch the list of useable qualities across all extruders.
@@ -55,8 +58,8 @@ class UserProfilesModel(ProfilesModel):
             # If the printer has multiple extruders then quality changes related to the current extruder are kept
             filtered_quality_changes = [qc for qc in quality_changes_list if qc.getMetaDataEntry("quality_type") in quality_type_set and
                                         qc.getMetaDataEntry("extruder") is not None and
-                                        qc.getMetaDataEntry("extruder") == active_extruder.definition.getMetaDataEntry("quality_definition") or
-                                        qc.getMetaDataEntry("extruder") == active_extruder.definition.getId()]
+                                        (qc.getMetaDataEntry("extruder") == active_extruder.definition.getMetaDataEntry("quality_definition") or
+                                         qc.getMetaDataEntry("extruder") == active_extruder.definition.getId())]
         else:
             # If not, the quality changes of the global stack are selected
             filtered_quality_changes = [qc for qc in quality_changes_list if qc.getMetaDataEntry("quality_type") in quality_type_set and
diff --git a/plugins/3MFReader/WorkspaceDialog.py b/plugins/3MFReader/WorkspaceDialog.py
index 7c803486eb..349dec177b 100644
--- a/plugins/3MFReader/WorkspaceDialog.py
+++ b/plugins/3MFReader/WorkspaceDialog.py
@@ -272,12 +272,18 @@ class WorkspaceDialog(QObject):
     def notifyClosed(self):
         self._result = {} # The result should be cleared before hide, because after it is released the main thread lock
         self._visible = False
-        self._lock.release()
+        try:
+            self._lock.release()
+        except:
+            pass
 
     def hide(self):
         self._visible = False
         self._view.hide()
-        self._lock.release()
+        try:
+            self._lock.release()
+        except:
+            pass
 
     @pyqtSlot()
     def onOkButtonClicked(self):
@@ -290,7 +296,6 @@ class WorkspaceDialog(QObject):
         self._view.hide()
         self.hide()
 
-
     ##  Block thread until the dialog is closed.
     def waitForClose(self):
         if self._visible:
diff --git a/plugins/3MFReader/WorkspaceDialog.qml b/plugins/3MFReader/WorkspaceDialog.qml
index ad1d21a491..55f8d5eecf 100644
--- a/plugins/3MFReader/WorkspaceDialog.qml
+++ b/plugins/3MFReader/WorkspaceDialog.qml
@@ -10,10 +10,11 @@ import UM 1.1 as UM
 
 UM.Dialog
 {
+    id: base
     title: catalog.i18nc("@title:window", "Open Project")
 
     minimumWidth: 500 * screenScaleFactor
-    minimumHeight: 400 * screenScaleFactor
+    minimumHeight: 450 * screenScaleFactor
     width: minimumWidth
     height: minimumHeight
 
@@ -30,6 +31,7 @@ UM.Dialog
             materialResolveComboBox.currentIndex = 0
         }
     }
+
     Item
     {
         anchors.fill: parent
@@ -377,7 +379,7 @@ UM.Dialog
             anchors.right: ok_button.left
             anchors.rightMargin: 2 * screenScaleFactor
         }
-         Button
+        Button
         {
             id: ok_button
             text: catalog.i18nc("@action:button","Open");
@@ -386,4 +388,10 @@ UM.Dialog
             anchors.right: parent.right
         }
     }
+
+    function reject() {
+        manager.onCancelButtonClicked();
+        base.visible = false;
+        base.rejected();
+    }
 }
diff --git a/plugins/ChangeLogPlugin/ChangeLog.txt b/plugins/ChangeLogPlugin/ChangeLog.txt
index 207493468e..57e6e05d9c 100755
--- a/plugins/ChangeLogPlugin/ChangeLog.txt
+++ b/plugins/ChangeLogPlugin/ChangeLog.txt
@@ -1,3 +1,6 @@
+[3.0.0]
+*Will be updated soon!
+
 [2.7.0]
 *Top surface skin
 Specify print settings of the top-most layers separately in order to improve print duration and achieve higher quality top surfaces.
diff --git a/plugins/CuraEngineBackend/CuraEngineBackend.py b/plugins/CuraEngineBackend/CuraEngineBackend.py
index c89f476fa9..914aa1dee0 100755
--- a/plugins/CuraEngineBackend/CuraEngineBackend.py
+++ b/plugins/CuraEngineBackend/CuraEngineBackend.py
@@ -441,7 +441,7 @@ class CuraEngineBackend(QObject, Backend):
 
     def _onStackErrorCheckFinished(self):
         self._is_error_check_scheduled = False
-        if self._need_slicing:
+        if not self._slicing and self._need_slicing:
             self.needsSlicing()
             self._onChanged()
 
@@ -536,7 +536,6 @@ class CuraEngineBackend(QObject, Backend):
     #
     #   \param message The protobuf message containing the print time per feature
     def _parseMessagePrintTimes(self, message):
-
         result = {
             "inset_0": message.time_inset_0,
             "inset_x": message.time_inset_x,
diff --git a/plugins/MachineSettingsAction/MachineSettingsAction.qml b/plugins/MachineSettingsAction/MachineSettingsAction.qml
index 613a28f3b7..cd7738da11 100644
--- a/plugins/MachineSettingsAction/MachineSettingsAction.qml
+++ b/plugins/MachineSettingsAction/MachineSettingsAction.qml
@@ -247,7 +247,7 @@ Cura.MachineAction
 
                                 Row
                                 {
-                                    spacing: UM.Theme.getSize("default_margin").width
+                                    spacing: UM.Theme.getSize("default_margin").width * 4 / 5
 
                                     Label
                                     {
@@ -648,7 +648,7 @@ Cura.MachineAction
 
             Row
             {
-                spacing: UM.Theme.getSize("default_margin").width
+                spacing: UM.Theme.getSize("default_margin").width * 4 / 5
 
                 Label
                 {
diff --git a/plugins/UM3NetworkPrinting/DiscoverUM3Action.qml b/plugins/UM3NetworkPrinting/DiscoverUM3Action.qml
index 1b68c7b15d..7dcda59068 100644
--- a/plugins/UM3NetworkPrinting/DiscoverUM3Action.qml
+++ b/plugins/UM3NetworkPrinting/DiscoverUM3Action.qml
@@ -321,7 +321,7 @@ Cura.MachineAction
         title: catalog.i18nc("@title:window", "Printer Address")
 
         minimumWidth: 400 * screenScaleFactor
-        minimumHeight: 120 * screenScaleFactor
+        minimumHeight: 130 * screenScaleFactor
         width: minimumWidth
         height: minimumHeight
 
diff --git a/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py b/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
index 5e9f281d63..fca9670b40 100755
--- a/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
+++ b/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
@@ -23,16 +23,14 @@ from PyQt5.QtWidgets import QMessageBox
 import json
 import os
 import gzip
-import zlib
 
 from time import time
-from time import sleep
+
 from time import gmtime
+from enum import IntEnum
 
 i18n_catalog = i18nCatalog("cura")
 
-from enum import IntEnum
-
 class AuthState(IntEnum):
     NotAuthenticated = 1
     AuthenticationRequested = 2
@@ -335,13 +333,17 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
             self._camera_timer.stop()
 
         if self._image_reply:
+            skip_abort = False
             try:
                 try:
                     self._image_reply.downloadProgress.disconnect(self._onStreamDownloadProgress)
-                except TypeError:
-                    pass #The signal was never connected.
-                self._image_reply.abort()
-            except RuntimeError:
+                except Exception as e:
+                    if type(e) != RuntimeError: # can happen the RuntimeError occurs before calling abort (=see below), then then the application will crash
+                        skip_abort = True
+                        pass #The signal was never connected.
+                if not skip_abort:
+                    self._image_reply.abort()
+            except Exception as e: #RuntimeError
                 pass  # It can happen that the wrapped c++ object is already deleted.
             self._image_reply = None
             self._image_request = None
@@ -528,6 +530,9 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
         self._last_request_time = time()
 
     def _finalizePostReply(self):
+        # Indicate uploading was finished (so another file can be send)
+        self._write_finished = True
+
         if self._post_reply is None:
             return
 
@@ -836,6 +841,7 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
             Logger.log("d", "User aborted sending print to remote.")
             self._progress_message.hide()
             self._compressing_print = False
+            self._write_finished = True  # post_reply does not always exist, so make sure we unblock writing
             if self._post_reply:
                 self._finalizePostReply()
             Application.getInstance().showPrintMonitor.emit(False)
@@ -1203,6 +1209,7 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
                 # Remove cached post request items.
                 del self._material_post_objects[id(reply)]
             elif "print_job" in reply_url:
+                self._onUploadFinished()  # Make sure the upload flag is reset as reply.finished is not always triggered
                 try:
                     reply.uploadProgress.disconnect(self._onUploadProgress)
                 except:
diff --git a/plugins/UM3NetworkPrinting/PrinterInfoBlock.qml b/plugins/UM3NetworkPrinting/PrinterInfoBlock.qml
index da5ebc7e37..25be77bd7d 100644
--- a/plugins/UM3NetworkPrinting/PrinterInfoBlock.qml
+++ b/plugins/UM3NetworkPrinting/PrinterInfoBlock.qml
@@ -189,7 +189,7 @@ Rectangle
                 PrintCoreConfiguration
                 {
                     id: leftExtruderInfo
-                    width: (parent.width - extruderSeperator.width) / 2
+                    width: Math.floor((parent.width - extruderSeperator.width) / 2)
                     printCoreConfiguration: printer.configuration[0]
                 }
 
@@ -204,7 +204,7 @@ Rectangle
                 PrintCoreConfiguration
                 {
                     id: rightExtruderInfo
-                    width: (parent.width - extruderSeperator.width) / 2
+                    width: Math.floor((parent.width - extruderSeperator.width) / 2)
                     printCoreConfiguration: printer.configuration[1]
                 }
             }
@@ -404,6 +404,8 @@ Rectangle
                         anchors.left: parent.left
                         anchors.right: parent.right
                         elide: Text.ElideRight
+                        wrapMode: Text.Wrap
+
                         font: UM.Theme.getFont("default")
                     }
 
diff --git a/plugins/VersionUpgrade/VersionUpgrade25to26/VersionUpgrade25to26.py b/plugins/VersionUpgrade/VersionUpgrade25to26/VersionUpgrade25to26.py
index 2c598ad766..e1c14be2e1 100644
--- a/plugins/VersionUpgrade/VersionUpgrade25to26/VersionUpgrade25to26.py
+++ b/plugins/VersionUpgrade/VersionUpgrade25to26/VersionUpgrade25to26.py
@@ -127,7 +127,12 @@ class VersionUpgrade25to26(VersionUpgrade):
         machine_id = parser["general"]["id"]
         quality_container_id = parser["containers"]["2"]
         material_container_id = parser["containers"]["3"]
-        definition_container_id = parser["containers"]["6"]
+
+        # we don't have definition_changes container in 2.5
+        if "6" in parser["containers"]:
+            definition_container_id = parser["containers"]["6"]
+        else:
+            definition_container_id = parser["containers"]["5"]
 
         if definition_container_id == "custom" and not self._checkCustomFdmPrinterHasExtruderStack(machine_id):
             # go through all extruders and make sure that this custom FDM printer has 8 extruder stacks.
diff --git a/plugins/VersionUpgrade/VersionUpgrade27to30/VersionUpgrade27to30.py b/plugins/VersionUpgrade/VersionUpgrade27to30/VersionUpgrade27to30.py
index 3b1b854761..d0b78168b4 100644
--- a/plugins/VersionUpgrade/VersionUpgrade27to30/VersionUpgrade27to30.py
+++ b/plugins/VersionUpgrade/VersionUpgrade27to30/VersionUpgrade27to30.py
@@ -117,8 +117,25 @@ class VersionUpgrade27to30(VersionUpgrade):
         # Set the definition to "ultimaker2" for Ultimaker 2 quality changes
         if not parser.has_section("general"):
             parser.add_section("general")
-        if os.path.basename(filename).startswith("ultimaker2_"):
-            parser["general"]["definition"] = "ultimaker2"
+
+        # Need to exclude the following names:
+        # - ultimaker2_plus
+        # - ultimaker2_go
+        # - ultimaker2_extended
+        # - ultimaker2_extended_plus
+        exclude_prefix_list = ["ultimaker2_plus_",
+                               "ultimaker2_go_",
+                               "ultimaker2_extended_",
+                               "ultimaker2_extended_plus_"]
+        file_base_name = os.path.basename(filename)
+        if file_base_name.startswith("ultimaker2_"):
+            skip_this = False
+            for exclude_prefix in exclude_prefix_list:
+                if file_base_name.startswith(exclude_prefix):
+                    skip_this = True
+                    break
+            if not skip_this:
+                parser["general"]["definition"] = "ultimaker2"
 
         # Update version numbers
         parser["general"]["version"] = "2"
diff --git a/resources/qml/Preferences/MaterialView.qml b/resources/qml/Preferences/MaterialView.qml
index c1750b2342..b13ce1aadf 100644
--- a/resources/qml/Preferences/MaterialView.qml
+++ b/resources/qml/Preferences/MaterialView.qml
@@ -16,8 +16,8 @@ TabView
 
     property bool editingEnabled: false;
     property string currency: UM.Preferences.getValue("cura/currency") ? UM.Preferences.getValue("cura/currency") : "€"
-    property real firstColumnWidth: (width * 0.45) | 0
-    property real secondColumnWidth: (width * 0.45) | 0
+    property real firstColumnWidth: (width * 0.50) | 0
+    property real secondColumnWidth: (width * 0.40) | 0
     property string containerId: ""
     property var materialPreferenceValues: UM.Preferences.getValue("cura/material_settings") ? JSON.parse(UM.Preferences.getValue("cura/material_settings")) : {}