diff --git a/cura/PrinterOutput/FirmwareUpdater.py b/cura/PrinterOutput/FirmwareUpdater.py
index d33015920a..3f20e0f3c4 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 90a27c24e1..b5b6c15f50 100644
--- a/plugins/FirmwareUpdater/FirmwareUpdaterMachineAction.qml
+++ b/plugins/FirmwareUpdater/FirmwareUpdaterMachineAction.qml
@@ -151,8 +151,6 @@ 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/USBPrinting/AvrFirmwareUpdater.py b/plugins/USBPrinting/AvrFirmwareUpdater.py
index ded2036efe..0f7146560d 100644
--- a/plugins/USBPrinting/AvrFirmwareUpdater.py
+++ b/plugins/USBPrinting/AvrFirmwareUpdater.py
@@ -27,9 +27,6 @@ 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 3c5c66d805..671f1788f7 100644
--- a/plugins/USBPrinting/avr_isp/intelHex.py
+++ b/plugins/USBPrinting/avr_isp/intelHex.py
@@ -5,16 +5,13 @@ 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: str) -> List[int]:
+def readHex(filename):
     """
     Read an verify an intel hex file. Return the data as an list of bytes.
     """
-    data = []  # type: List[int]
+    data = []
     extra_addr = 0
     f = io.open(filename, "r", encoding = "utf-8")
     for line in f: