diff --git a/src/components/versioning/FieldHistoryDialog.tsx b/src/components/versioning/FieldHistoryDialog.tsx
index 5fc21ae1..f0161118 100644
--- a/src/components/versioning/FieldHistoryDialog.tsx
+++ b/src/components/versioning/FieldHistoryDialog.tsx
@@ -88,6 +88,7 @@ export function FieldHistoryDialog({
         setChanges(mergedData as FieldChange[]);
       } catch (error) {
         console.error('Error fetching field history:', error);
+        setChanges([]);
       } finally {
         setLoading(false);
       }
diff --git a/src/hooks/useEntityVersions.ts b/src/hooks/useEntityVersions.ts
index e94727e7..17c8a4c1 100644
--- a/src/hooks/useEntityVersions.ts
+++ b/src/hooks/useEntityVersions.ts
@@ -65,10 +65,16 @@ export function useEntityVersions(entityType: string, entityId: string) {
         .select('user_id, username, avatar_url')
         .in('user_id', userIds);
 
-      const versionsWithProfiles = data?.map(v => ({
-        ...v,
-        changer_profile: profiles?.find(p => p.user_id === v.changed_by)
-      })) as EntityVersion[];
+      const versionsWithProfiles = data?.map(v => {
+        const profile = profiles?.find(p => p.user_id === v.changed_by);
+        return {
+          ...v,
+          changer_profile: profile || {
+            username: 'Unknown',
+            avatar_url: null
+          }
+        };
+      }) as EntityVersion[];
 
       // Only update state if component is still mounted
       if (isMountedRef.current) {
diff --git a/src/hooks/useLocationAutoDetect.ts b/src/hooks/useLocationAutoDetect.ts
index 6da98f56..0e3f5d65 100644
--- a/src/hooks/useLocationAutoDetect.ts
+++ b/src/hooks/useLocationAutoDetect.ts
@@ -2,6 +2,20 @@ import { useEffect } from 'react';
 import { useAuth } from '@/hooks/useAuth';
 import { useUnitPreferences } from '@/hooks/useUnitPreferences';
 
+function isLocalStorageAvailable(): boolean {
+  try {
+    if (typeof window === 'undefined' || typeof localStorage === 'undefined') {
+      return false;
+    }
+    const testKey = '__localStorage_test__';
+    localStorage.setItem(testKey, 'test');
+    localStorage.removeItem(testKey);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
 export function useLocationAutoDetect() {
   const { user } = useAuth();
   const { preferences, autoDetectPreferences, loading } = useUnitPreferences();
@@ -10,16 +24,26 @@ export function useLocationAutoDetect() {
     // Only run auto-detection after preferences have loaded
     if (loading) return;
     
+    // Check if localStorage is available
+    if (!isLocalStorageAvailable()) {
+      console.warn('localStorage is not available, skipping location auto-detection');
+      return;
+    }
+    
     // Check if we've already attempted detection
     const hasAttemptedDetection = localStorage.getItem('location_detection_attempted');
     
     // Auto-detect if we haven't attempted it yet and auto_detect is enabled
     if (preferences.auto_detect && !hasAttemptedDetection) {
       autoDetectPreferences().then(() => {
-        localStorage.setItem('location_detection_attempted', 'true');
+        if (isLocalStorageAvailable()) {
+          localStorage.setItem('location_detection_attempted', 'true');
+        }
       }).catch((error) => {
         console.error('❌ Failed to auto-detect location:', error);
-        localStorage.setItem('location_detection_attempted', 'true');
+        if (isLocalStorageAvailable()) {
+          localStorage.setItem('location_detection_attempted', 'true');
+        }
       });
     }
   }, [user, loading, preferences.auto_detect]);
diff --git a/supabase/functions/process-selective-approval/index.ts b/supabase/functions/process-selective-approval/index.ts
index 90bcc120..ca97e9fb 100644
--- a/supabase/functions/process-selective-approval/index.ts
+++ b/supabase/functions/process-selective-approval/index.ts
@@ -318,9 +318,10 @@ function topologicalSort(items: any[]): any[] {
 
     if (item.depends_on) {
       const parent = items.find(i => i.id === item.depends_on);
-      if (parent) {
-        visit(parent);
+      if (!parent) {
+        throw new Error(`Missing dependency: item ${item.id} depends on ${item.depends_on} which is not in the submission`);
       }
+      visit(parent);
     }
 
     visiting.delete(item.id);