diff --git a/cura/PrinterOutput/FirmwareUpdater.py b/cura/PrinterOutput/FirmwareUpdater.py
index 3f20e0f3c4..d33015920a 100644
--- a/cura/PrinterOutput/FirmwareUpdater.py
+++ b/cura/PrinterOutput/FirmwareUpdater.py
@@ -75,4 +75,4 @@ class FirmwareUpdateState(IntEnum):
     communication_error = 4
     io_error = 5
     firmware_not_found_error = 6
-
+    invalid_firmware_error = 7
diff --git a/plugins/FirmwareUpdater/FirmwareUpdaterMachineAction.qml b/plugins/FirmwareUpdater/FirmwareUpdaterMachineAction.qml
index b5b6c15f50..90a27c24e1 100644
--- a/plugins/FirmwareUpdater/FirmwareUpdaterMachineAction.qml
+++ b/plugins/FirmwareUpdater/FirmwareUpdaterMachineAction.qml
@@ -151,6 +151,8 @@ Cura.MachineAction
                             return catalog.i18nc("@label","Firmware update failed due to an input/output error.");
                         case 6:
                             return catalog.i18nc("@label","Firmware update failed due to missing firmware.");
+                        case 7:
+                            return catalog.i18nc("@label","Firmware update failed due to invalid firmware file.");
                     }
                 }
 
diff --git a/plugins/UM3NetworkPrinting/src/Network/LocalClusterOutputDeviceManager.py b/plugins/UM3NetworkPrinting/src/Network/LocalClusterOutputDeviceManager.py
index e55eb12fed..89fd71d03c 100644
--- a/plugins/UM3NetworkPrinting/src/Network/LocalClusterOutputDeviceManager.py
+++ b/plugins/UM3NetworkPrinting/src/Network/LocalClusterOutputDeviceManager.py
@@ -135,10 +135,13 @@ class LocalClusterOutputDeviceManager:
         ultimaker_machines = container_registry.findContainersMetadata(type="machine", manufacturer="Ultimaker B.V.")
         found_machine_type_identifiers = {}  # type: Dict[str, str]
         for machine in ultimaker_machines:
-            machine_bom_number = machine.get("firmware_update_info", {}).get("id", None)
             machine_type = machine.get("id", None)
-            if machine_bom_number and machine_type:
-                found_machine_type_identifiers[str(machine_bom_number)] = machine_type
+            machine_bom_numbers = machine.get("bom_numbers", [])
+            if machine_type and machine_bom_numbers:
+                for bom_number in machine_bom_numbers:
+                    # This produces a n:1 mapping of bom numbers to machine types
+                    # allowing the S5R1 and S5R2 hardware to use a single S5 definition.
+                    found_machine_type_identifiers[str(bom_number)] = machine_type
         return found_machine_type_identifiers
 
     ## Add a new device.
diff --git a/plugins/USBPrinting/AvrFirmwareUpdater.py b/plugins/USBPrinting/AvrFirmwareUpdater.py
index 0f7146560d..ded2036efe 100644
--- a/plugins/USBPrinting/AvrFirmwareUpdater.py
+++ b/plugins/USBPrinting/AvrFirmwareUpdater.py
@@ -27,6 +27,9 @@ class AvrFirmwareUpdater(FirmwareUpdater):
         except (FileNotFoundError, AssertionError):
             Logger.log("e", "Unable to read provided hex file. Could not update firmware.")
             self._setFirmwareUpdateState(FirmwareUpdateState.firmware_not_found_error)
+        except Exception:
+            Logger.logException("e", "Failed to read hex file '%s'", self._firmware_file)
+            self._setFirmwareUpdateState(FirmwareUpdateState.invalid_firmware_error)
             return
 
         programmer = stk500v2.Stk500v2()
diff --git a/plugins/USBPrinting/avr_isp/intelHex.py b/plugins/USBPrinting/avr_isp/intelHex.py
index 671f1788f7..3c5c66d805 100644
--- a/plugins/USBPrinting/avr_isp/intelHex.py
+++ b/plugins/USBPrinting/avr_isp/intelHex.py
@@ -5,13 +5,16 @@ See: http://en.wikipedia.org/wiki/Intel_HEX
 This is a python 3 conversion of the code created by David Braam for the Cura project.
 """
 import io
+from typing import List
+
 from UM.Logger import Logger
 
-def readHex(filename):
+
+def readHex(filename: str) -> List[int]:
     """
     Read an verify an intel hex file. Return the data as an list of bytes.
     """
-    data = []
+    data = []  # type: List[int]
     extra_addr = 0
     f = io.open(filename, "r", encoding = "utf-8")
     for line in f:
diff --git a/resources/definitions/ultimaker3.def.json b/resources/definitions/ultimaker3.def.json
index bd7e96448a..b34ff3bdba 100644
--- a/resources/definitions/ultimaker3.def.json
+++ b/resources/definitions/ultimaker3.def.json
@@ -33,7 +33,10 @@
                 "https://software.ultimaker.com/releases/firmware/9066/stable/um-update.swu.version"
             ],
             "update_url": "https://ultimaker.com/firmware"
-        }
+        },
+        "bom_numbers": [
+            9066
+        ]
     },
 
 
diff --git a/resources/definitions/ultimaker3_extended.def.json b/resources/definitions/ultimaker3_extended.def.json
index c0d099366d..ba9824896f 100644
--- a/resources/definitions/ultimaker3_extended.def.json
+++ b/resources/definitions/ultimaker3_extended.def.json
@@ -30,7 +30,10 @@
                 "https://software.ultimaker.com/releases/firmware/9066/stable/um-update.swu.version"
             ],
             "update_url": "https://ultimaker.com/firmware"
-        }
+        },
+        "bom_numbers": [
+            9511
+        ]
     },
 
     "overrides": {
diff --git a/resources/definitions/ultimaker_s3.def.json b/resources/definitions/ultimaker_s3.def.json
index 0fbf4acd77..f7f3a038fe 100644
--- a/resources/definitions/ultimaker_s3.def.json
+++ b/resources/definitions/ultimaker_s3.def.json
@@ -34,7 +34,10 @@
             "id": 213482,
             "check_urls": ["https://software.ultimaker.com/releases/firmware/213482/stable/um-update.swu.version"],
             "update_url": "https://ultimaker.com/firmware"
-        }
+        },
+        "bom_numbers": [
+            213482
+        ]
     },
 
     "overrides": {
diff --git a/resources/definitions/ultimaker_s5.def.json b/resources/definitions/ultimaker_s5.def.json
index 81b3a704ff..fef8c87c27 100644
--- a/resources/definitions/ultimaker_s5.def.json
+++ b/resources/definitions/ultimaker_s5.def.json
@@ -35,7 +35,10 @@
             "id": 9051,
             "check_urls": ["https://software.ultimaker.com/releases/firmware/9051/stable/um-update.swu.version"],
             "update_url": "https://ultimaker.com/firmware"
-        }
+        },
+        "bom_numbers": [
+            9051, 214475
+        ]
     },
 
     "overrides": {