diff --git a/src/main/java/li/cil/oc2/api/bus/device/data/FirmwareLoader.java b/src/main/java/li/cil/oc2/api/bus/device/data/FirmwareLoader.java
new file mode 100644
index 00000000..bc392dd3
--- /dev/null
+++ b/src/main/java/li/cil/oc2/api/bus/device/data/FirmwareLoader.java
@@ -0,0 +1,12 @@
+package li.cil.oc2.api.bus.device.data;
+
+import li.cil.oc2.api.bus.device.vm.VMDevice;
+
+/**
+ * This interface serves as a marker for devices that load firmware.
+ * <p>
+ * It is used exclusively to check if some firmware will be loaded early in the
+ * startup process, to provide a useful error to the user if none is present.
+ */
+public interface FirmwareLoader extends VMDevice {
+}
diff --git a/src/main/java/li/cil/oc2/common/bus/device/item/ByteBufferFlashMemoryVMDevice.java b/src/main/java/li/cil/oc2/common/bus/device/item/ByteBufferFlashMemoryVMDevice.java
index a1e9b9fb..73f73c38 100644
--- a/src/main/java/li/cil/oc2/common/bus/device/item/ByteBufferFlashMemoryVMDevice.java
+++ b/src/main/java/li/cil/oc2/common/bus/device/item/ByteBufferFlashMemoryVMDevice.java
@@ -2,6 +2,7 @@ package li.cil.oc2.common.bus.device.item;
 
 import com.google.common.eventbus.Subscribe;
 import li.cil.oc2.api.bus.device.ItemDevice;
+import li.cil.oc2.api.bus.device.data.FirmwareLoader;
 import li.cil.oc2.api.bus.device.vm.VMContext;
 import li.cil.oc2.api.bus.device.vm.VMDevice;
 import li.cil.oc2.api.bus.device.vm.VMDeviceLoadResult;
@@ -21,7 +22,7 @@ import java.nio.ByteBuffer;
 import java.util.OptionalLong;
 
 @SuppressWarnings("UnstableApiUsage")
-public final class ByteBufferFlashMemoryVMDevice extends IdentityProxy<ItemStack> implements VMDevice, ItemDevice {
+public final class ByteBufferFlashMemoryVMDevice extends IdentityProxy<ItemStack> implements VMDevice, ItemDevice, FirmwareLoader {
     public static final String DATA_TAG_NAME = "data";
 
     ///////////////////////////////////////////////////////////////
diff --git a/src/main/java/li/cil/oc2/common/bus/device/item/FirmwareFlashMemoryVMDevice.java b/src/main/java/li/cil/oc2/common/bus/device/item/FirmwareFlashMemoryVMDevice.java
index 705691db..138655ee 100644
--- a/src/main/java/li/cil/oc2/common/bus/device/item/FirmwareFlashMemoryVMDevice.java
+++ b/src/main/java/li/cil/oc2/common/bus/device/item/FirmwareFlashMemoryVMDevice.java
@@ -3,6 +3,7 @@ package li.cil.oc2.common.bus.device.item;
 import com.google.common.eventbus.Subscribe;
 import li.cil.oc2.api.bus.device.ItemDevice;
 import li.cil.oc2.api.bus.device.data.Firmware;
+import li.cil.oc2.api.bus.device.data.FirmwareLoader;
 import li.cil.oc2.api.bus.device.vm.VMContext;
 import li.cil.oc2.api.bus.device.vm.VMDevice;
 import li.cil.oc2.api.bus.device.vm.VMDeviceLoadResult;
@@ -15,7 +16,7 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.util.text.TranslationTextComponent;
 
 @SuppressWarnings("UnstableApiUsage")
-public final class FirmwareFlashMemoryVMDevice extends IdentityProxy<ItemStack> implements VMDevice, ItemDevice {
+public final class FirmwareFlashMemoryVMDevice extends IdentityProxy<ItemStack> implements VMDevice, ItemDevice, FirmwareLoader {
     private final Firmware firmware;
     private MemoryMap memoryMap;
 
diff --git a/src/main/java/li/cil/oc2/common/serialization/serializers/JsonArraySerializer.java b/src/main/java/li/cil/oc2/common/serialization/serializers/JsonArraySerializer.java
index 3332310e..96af5a72 100644
--- a/src/main/java/li/cil/oc2/common/serialization/serializers/JsonArraySerializer.java
+++ b/src/main/java/li/cil/oc2/common/serialization/serializers/JsonArraySerializer.java
@@ -16,6 +16,7 @@ public final class JsonArraySerializer implements Serializer<JsonArray> {
         visitor.putObject("value", String.class, jsonArray.toString());
     }
 
+    @Nullable
     @Override
     public JsonArray deserialize(final DeserializationVisitor visitor, final Class<JsonArray> type, @Nullable final Object value) throws SerializationException {
         JsonArray array = (JsonArray) value;
diff --git a/src/main/java/li/cil/oc2/common/serialization/serializers/TextComponentSerializer.java b/src/main/java/li/cil/oc2/common/serialization/serializers/TextComponentSerializer.java
index 8e6a0a44..28bacf6a 100644
--- a/src/main/java/li/cil/oc2/common/serialization/serializers/TextComponentSerializer.java
+++ b/src/main/java/li/cil/oc2/common/serialization/serializers/TextComponentSerializer.java
@@ -15,6 +15,7 @@ public final class TextComponentSerializer implements Serializer<ITextComponent>
         visitor.putObject("value", String.class, json);
     }
 
+    @Nullable
     @Override
     public ITextComponent deserialize(final DeserializationVisitor visitor, final Class<ITextComponent> type, @Nullable final Object value) throws SerializationException {
         if (!visitor.exists("value")) {
diff --git a/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachineState.java b/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachineState.java
index a2945e1f..1b9a6720 100644
--- a/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachineState.java
+++ b/src/main/java/li/cil/oc2/common/vm/AbstractVirtualMachineState.java
@@ -1,5 +1,6 @@
 package li.cil.oc2.common.vm;
 
+import li.cil.oc2.api.bus.device.data.FirmwareLoader;
 import li.cil.oc2.api.bus.device.vm.VMDeviceLoadResult;
 import li.cil.oc2.api.bus.device.vm.event.VMPausingEvent;
 import li.cil.oc2.common.Constants;
@@ -24,8 +25,6 @@ public abstract class AbstractVirtualMachineState<TBusController extends Abstrac
 
     ///////////////////////////////////////////////////////////////////
 
-    ///////////////////////////////////////////////////////////////////
-
     private static final String VIRTUAL_MACHINE_TAG_NAME = "virtualMachine";
     private static final String RUNNER_TAG_NAME = "runner";
 
@@ -190,6 +189,11 @@ public abstract class AbstractVirtualMachineState<TBusController extends Abstrac
                     break;
                 }
 
+                if (busController.getDevices().stream().noneMatch(device -> device instanceof FirmwareLoader)) {
+                    setBootError(new TranslationTextComponent(Constants.COMPUTER_ERROR_MISSING_FIRMWARE));
+                    setRunState(RunState.STOPPED);
+                    break;
+                }
 
                 // May have a valid runner after load. In which case we just had to wait for
                 // bus setup and devices to load. So we can keep using it.
@@ -205,12 +209,12 @@ public abstract class AbstractVirtualMachineState<TBusController extends Abstrac
                         // forgotten to add some RAM modules.
                         setBootError(new TranslationTextComponent(Constants.COMPUTER_ERROR_INSUFFICIENT_MEMORY));
                         setRunState(RunState.STOPPED);
-                        return;
+                        break;
                     } catch (final MemoryAccessException e) {
                         LOGGER.error(e);
                         setBootError(new TranslationTextComponent(Constants.COMPUTER_ERROR_UNKNOWN));
                         setRunState(RunState.STOPPED);
-                        return;
+                        break;
                     }
 
                     runner = createRunner();
diff --git a/src/main/resources/assets/oc2/lang/en_us.json b/src/main/resources/assets/oc2/lang/en_us.json
index 0516b13d..f8f98092 100644
--- a/src/main/resources/assets/oc2/lang/en_us.json
+++ b/src/main/resources/assets/oc2/lang/en_us.json
@@ -37,7 +37,7 @@
   "config.oc2.admin.fakePlayerUUID": "Fake Player UUID",
 
   "gui.oc2.computer.error.unknown": "Unknown Error",
-  "gui.oc2.computer.error.missing_firmware": "Missing Flash Memory",
+  "gui.oc2.computer.error.missing_firmware": "Missing Firmware",
   "gui.oc2.computer.error.insufficient_memory": "Insufficient Memory",
   "gui.oc2.computer.bus_state.incomplete": "Bus Incomplete",
   "gui.oc2.computer.bus_state.too_complex": "Bus Too Complex",