diff --git a/frontend/src/OrderHistoryPanel.tsx b/frontend/src/OrderHistoryPanel.tsx
index 3fbf331..a945134 100644
--- a/frontend/src/OrderHistoryPanel.tsx
+++ b/frontend/src/OrderHistoryPanel.tsx
@@ -30,6 +30,8 @@ function OrderHistoryPanel({context}: {context: any}) {
 
     const [ loading, setLoading ] = useState<boolean>(true);
 
+    const [ error, setError ] = useState<boolean>(false);
+
     // Plugin settings object
     const pluginSettings = useMemo(() => context?.context?.settings ?? {}, [context]);
 
@@ -197,7 +199,7 @@ function OrderHistoryPanel({context}: {context: any}) {
 
     // Ensure that the selected order type is valid for the current context
     useEffect(() => {
-        if (!validOrderTypes.find((type) => type.value == orderType)) {
+        if (!validOrderTypes.find((type: any) => type.value == orderType)) {
             setOrderType(validOrderTypes[0]?.value ?? null);
         }
     }, [orderType, validOrderTypes]);
@@ -240,10 +242,12 @@ function OrderHistoryPanel({context}: {context: any}) {
             }).then((response: any) => {
                 setHistoryData(response.data);
                 setLoading(false);
+                setError(false);
             }).catch(() => {
                 console.error("ERR: Failed to fetch history data");
                 setHistoryData([]);
                 setLoading(false);
+                setError(true);
             });
         }
 
@@ -391,6 +395,11 @@ function OrderHistoryPanel({context}: {context: any}) {
         <Paper withBorder p="sm" m="sm">
             <Box pos="relative">
             <LoadingOverlay visible={loading} />
+            {error && (
+                <Alert color="red" title="Error Loading Data">
+                    <Text>Failed to load order history data from the server</Text>
+                </Alert>
+            )}
             {(hasData || loading) ? (
                 <Card>
                 <BarChart
diff --git a/order_history/version.py b/order_history/version.py
index 3d1aa2e..51395e9 100644
--- a/order_history/version.py
+++ b/order_history/version.py
@@ -1,3 +1,3 @@
 """Version information for the Order History plugin."""
 
-PLUGIN_VERSION = "0.3.2"
+PLUGIN_VERSION = "0.3.3"
diff --git a/order_history/views.py b/order_history/views.py
index 5e3e453..860b9df 100644
--- a/order_history/views.py
+++ b/order_history/views.py
@@ -94,6 +94,10 @@ def generate_build_order_history(self):
         for build in builds:
             part = build.part
 
+            if not part:
+                # Skip builds which do not map to a part (may have been deleted, for example)
+                continue
+
             if part.pk not in parts:
                 parts[part.pk] = part
 
@@ -156,6 +160,11 @@ def generate_purchase_order_history(self):
         parts = {}
 
         for line in lines:
+
+            if not line.part or not line.part.part:
+                # Skip lines which do not map to a part (may have been deleted, for example)
+                continue
+
             part = line.part.part
 
             part_history = history_items.get(part.pk, None) or {}
@@ -215,6 +224,10 @@ def generate_sales_order_history(self):
         for line in lines:
             part = line.part
 
+            if not part:
+                # Skip lines which do not map to a part (may have been deleted, for example)
+                continue
+
             # Extract the date key for the line item
             part_history = history_items.get(part.pk, None) or {}
 
@@ -268,6 +281,10 @@ def generate_return_order_history(self):
         for line in lines:
             part = line.item.part
 
+            if not part:
+                # Skip lines which do not map to a part (may have been deleted, for example)
+                continue
+
             # Extract the date key for the line item
             part_history = history_items.get(part.pk, None) or {}