diff --git a/frontend/src/components/common/toast/ToastContainer.vue b/frontend/src/components/common/toast/ToastContainer.vue
index e603b1af..bc3b5c32 100644
--- a/frontend/src/components/common/toast/ToastContainer.vue
+++ b/frontend/src/components/common/toast/ToastContainer.vue
@@ -38,7 +38,7 @@ const handleRemoveToast = (id: string) => {
     position: fixed;
     top: 80px;
     right: 1.5rem;
-    z-index: 1000;
+    z-index: 2000;
     pointer-events: none;
     
     @media (max-width: 768px) {
diff --git a/frontend/src/components/project/task/AssetThumbnailCell.vue b/frontend/src/components/project/task/AssetThumbnailCell.vue
index 42c9b01f..ae96ad69 100644
--- a/frontend/src/components/project/task/AssetThumbnailCell.vue
+++ b/frontend/src/components/project/task/AssetThumbnailCell.vue
@@ -1,5 +1,10 @@
 <template>
-    <div class="asset-preview-cell" @mouseenter="onMouseEnter" @mouseleave="onMouseLeave">
+    <div
+        class="asset-preview-cell"
+        :class="{ clickable: isClickable }"
+        @mouseenter="onMouseEnter"
+        @mouseleave="onMouseLeave"
+    >
         <div class="asset-thumbnail">
             <img 
                 :src="getAssetThumbnailUrl(projectId, task.assetId)" 
@@ -93,6 +98,7 @@ interface Props {
     task: TaskTableRow;
     projectId: number;
     allTasks: TaskTableRow[];
+    isClickable?: boolean;
 }
 
 interface Emits {
@@ -138,7 +144,7 @@ const onImageError = (event: Event) => {
     display: flex;
     align-items: center;
     justify-content: center;
-    cursor: pointer;
+    cursor: inherit;
     padding: 0.5rem;
     
     .asset-thumbnail {
@@ -254,15 +260,16 @@ const onImageError = (event: Event) => {
             z-index: 1;
         }
     }
-    
-    &:hover {
+    &.clickable { cursor: pointer; }
+
+    &.clickable:hover {
         .asset-thumbnail {
             border-color: var(--color-primary);
-            
+
             .thumbnail-image:not(.loading) {
                 transform: scale(1.02);
             }
         }
     }
 }
-</style>
\ No newline at end of file
+</style>
diff --git a/frontend/src/core/workspace/loader/workspaceLoader.ts b/frontend/src/core/workspace/loader/workspaceLoader.ts
index 432cfae6..8627c49a 100644
--- a/frontend/src/core/workspace/loader/workspaceLoader.ts
+++ b/frontend/src/core/workspace/loader/workspaceLoader.ts
@@ -235,8 +235,12 @@ export class WorkspaceLoader {
             } else {
                 logger.warn(`No tasks found for asset ${assetId}`);
             }
-        } catch (taskError) {
+        } catch (taskError: any) {
             logger.error("Failed to fetch tasks:", taskError);
+            // Propagate access-redirect signals so the store/view can handle navigation + toast
+            if (taskError?.shouldRedirectToTask || taskError?.shouldRedirectToTaskView) {
+                throw taskError;
+            }
         }
 
         return result;
@@ -376,4 +380,4 @@ export class WorkspaceLoader {
 }
 
 // Export singleton instance
-export const workspaceLoader = new WorkspaceLoader();
\ No newline at end of file
+export const workspaceLoader = new WorkspaceLoader();
diff --git a/frontend/src/layouts/WorkspaceLayout.vue b/frontend/src/layouts/WorkspaceLayout.vue
index 061929a4..eef45c14 100644
--- a/frontend/src/layouts/WorkspaceLayout.vue
+++ b/frontend/src/layouts/WorkspaceLayout.vue
@@ -1,13 +1,18 @@
 <template>
     <div class="workspace-layout">
         <slot />
-        
+
+        <!-- Global toasts -->
+        <ToastContainer />
+
         <!-- Teleport target for floating action buttons -->
         <div id="fab-container"></div>
     </div>
 </template>
 
-<script setup lang="ts"></script>
+<script setup lang="ts">
+import ToastContainer from '@/components/common/toast/ToastContainer.vue';
+</script>
 
 <style scoped>
 .workspace-layout {
diff --git a/frontend/src/services/project/task/taskService.ts b/frontend/src/services/project/task/taskService.ts
index 5799b31a..06232145 100644
--- a/frontend/src/services/project/task/taskService.ts
+++ b/frontend/src/services/project/task/taskService.ts
@@ -348,25 +348,32 @@ class TaskService extends BaseProjectService {
             this.logger.info(`Fetched task ${taskId} successfully`);
             return task;
         } catch (error: any) {
+            // Normalize error fields from transformed ServerError or raw axios error
+            const status = error?.statusCode ?? error?.status ?? error?.response?.status;
+            const data = error?.serverResponse ?? error?.data ?? error?.response?.data;
+
             // Handle 409 Task assigned to another user with redirect to alternative task
-            if (error.status === 409 && error.data?.redirectToTask) {
-                // Create a special error that contains redirect information
-                const redirectError = new Error(error.data.message || 'This task is assigned to another user.');
-                (redirectError as any).redirectToTask = error.data.redirectToTask;
-                (redirectError as any).alternativeTask = error.data.alternativeTask;
-                (redirectError as any).toastMessage = error.data.toastMessage;
+            if (status === 409 && data?.redirectToTask) {
+                const redirectError = new Error(data.message || 'This task is assigned to another user.');
+                (redirectError as any).redirectToTask = data.redirectToTask;
+                (redirectError as any).alternativeTask = data.alternativeTask;
+                (redirectError as any).toastMessage = data.toastMessage;
                 throw redirectError;
             }
-            
+
             // Handle 404 No tasks available with redirect to task view
-            if (error.status === 404 && error.data?.redirectToTaskView) {
-                // Create a special error that contains redirect information
-                const redirectError = new Error(error.data.message || 'No tasks available for annotation.');
+            if (status === 404 && data?.redirectToTaskView) {
+                const redirectError = new Error(data.message || 'No tasks available for annotation.');
                 (redirectError as any).redirectToTaskView = true;
-                (redirectError as any).toastMessage = error.data.toastMessage;
+                (redirectError as any).toastMessage = data.toastMessage;
+                // Pass through explicit signal for "no tasks available"
+                const msg = (data?.error || data?.message || '').toString();
+                const noTasksFromMsg = /no\s*tasks\s*available/i.test(msg);
+                const noTasksFromCount = typeof data?.availableTasks === 'number' && data.availableTasks === 0;
+                (redirectError as any).noTasksAvailable = noTasksFromMsg || noTasksFromCount;
                 throw redirectError;
             }
-            
+
             // Re-throw other errors
             throw error;
         }
@@ -752,4 +759,4 @@ class TaskService extends BaseProjectService {
     }
 }
 
-export const taskService = new TaskService();
\ No newline at end of file
+export const taskService = new TaskService();
diff --git a/frontend/src/stores/workspaceStore.ts b/frontend/src/stores/workspaceStore.ts
index c729c0a0..73b2c8dc 100644
--- a/frontend/src/stores/workspaceStore.ts
+++ b/frontend/src/stores/workspaceStore.ts
@@ -356,7 +356,10 @@ export const useWorkspaceStore = defineStore("workspace", {
                     if (error?.shouldRedirectToTaskView) {
                         const redirectError = new Error(error.error || 'Task access denied');
                         (redirectError as any).redirectToTaskView = true;
-                        (redirectError as any).toastMessage = error.toastMessage || 'You cannot access this task.';
+                        (redirectError as any).noTasksAvailable = error.noTasksAvailable === true;
+                        (redirectError as any).toastMessage = error.toastMessage || (
+                            error.noTasksAvailable ? 'No tasks available to work on right now.' : 'You cannot access this task.'
+                        );
                         throw redirectError;
                     }
                     // For other task loading errors, log but continue
diff --git a/frontend/src/views/AnnotationWorkspace.vue b/frontend/src/views/AnnotationWorkspace.vue
index 705057a1..f5d7c7bd 100644
--- a/frontend/src/views/AnnotationWorkspace.vue
+++ b/frontend/src/views/AnnotationWorkspace.vue
@@ -421,44 +421,43 @@ onMounted(async () => {
     } catch (error: any) {
         // Handle redirect to alternative task
         if (error?.redirectToTask) {
-            showToast(
-                'Task Reassigned',
-                error.toastMessage || 'This task was assigned to another user. We found you an available task to work on.',
-                'info',
-                { duration: 5000 }
-            );
-            
-            // Redirect to the alternative task
             const alternativeTaskId = error.redirectToTask;
             const alternativeTask = error.alternativeTask;
             
-            // Navigate to the alternative task
-            router.replace({
+            // Load the alternative task in the workspace first
+            const targetAssetId = (alternativeTask?.assetId?.toString() || props.assetId);
+            await workspaceStore.loadAsset(props.projectId, targetAssetId, alternativeTaskId.toString());
+
+            // Navigate to the alternative task (update URL without re-mount)
+            await router.replace({
                 name: 'AnnotationWorkspace',
                 params: {
                     projectId: props.projectId,
-                    assetId: alternativeTask?.assetId?.toString() || props.assetId
+                    assetId: targetAssetId
                 },
                 query: {
                     taskId: alternativeTaskId.toString()
                 }
             });
+
+            // Show toast after navigation so it's visible in the new context
+            showToast(
+                'Task Reassigned',
+                error.toastMessage || 'This task was assigned to another user. We found you an available task to work on.',
+                'info',
+                { duration: 7500 }
+            );
             return;
         }
         
         // Handle task access errors and redirect to task view
         if (error?.redirectToTaskView) {
-            showToast(
-                'Access Denied',
-                error.toastMessage || 'You cannot access this task.',
-                'error',
-                { duration: 5000 }
-            );
-            
+            const noTasks = !!error.noTasksAvailable;
+
             // Redirect back to task view
             const currentTask = workspaceStore.getCurrentTask;
             if (currentTask) {
-                router.push({
+                await router.push({
                     name: 'StageTasks',
                     params: {
                         projectId: props.projectId,
@@ -468,13 +467,21 @@ onMounted(async () => {
                 });
             } else {
                 // Fallback to project dashboard if no current task context
-                router.push({
+                await router.push({
                     name: 'ProjectDashboard',
                     params: {
                         projectId: props.projectId
                     }
                 });
             }
+
+            // Show toast after navigation so it's visible on destination view
+            showToast(
+                noTasks ? 'All Tasks Complete' : 'Access Denied',
+                error.toastMessage || (noTasks ? 'No tasks available to work on right now.' : 'You cannot access this task.'),
+                noTasks ? 'info' : 'error',
+                { duration: 6000 }
+            );
             return;
         }
         
diff --git a/frontend/src/views/project/TasksView.vue b/frontend/src/views/project/TasksView.vue
index b08e9445..3abda2bd 100644
--- a/frontend/src/views/project/TasksView.vue
+++ b/frontend/src/views/project/TasksView.vue
@@ -114,6 +114,7 @@
                         :task="row"
                         :project-id="projectId"
                         :all-tasks="tasks"
+                        :is-clickable="row.isClickable"
                         @preview-show="showPreview"
                         @preview-hide="hidePreview"
                     />
@@ -1210,4 +1211,4 @@ onMounted(async () => {
         padding: 1rem;
     }
 }
-</style>
\ No newline at end of file
+</style>
diff --git a/server/Server/Services/TaskService.cs b/server/Server/Services/TaskService.cs
index 62d4ba2a..348d2995 100644
--- a/server/Server/Services/TaskService.cs
+++ b/server/Server/Services/TaskService.cs
@@ -231,59 +231,72 @@ public async Task<TaskDto> CreateTaskAsync(int projectId, CreateTaskDto createDt
             return null;
         }
 
-        // Validate task assignment before allowing modifications
-        if (!string.IsNullOrEmpty(updatingUserId))
-        {
-            await ValidateTaskAssignmentAsync(taskId, updatingUserId, "UPDATE");
-        }
-
-        // Update the task properties
-        if (updateDto.Priority.HasValue)
-        {
-            existingTask.Priority = updateDto.Priority.Value;
-        }
-
-        // Handle assignment - support both userId and email assignment
-        if (updateDto.AssignedToEmail != null)
+        // Determine what type of changes are requested
+        var isAssignmentChangeRequested = updateDto.AssignedToEmail != null || updateDto.AssignedToUserId != null;
+        var isNonAssignmentChangeRequested =
+            updateDto.Priority.HasValue ||
+            updateDto.DueDate.HasValue ||
+            updateDto.Status.HasValue ||
+            updateDto.WorkflowStageId.HasValue ||
+            updateDto.Metadata != null ||
+            updateDto.CompletedAt.HasValue ||
+            updateDto.ArchivedAt.HasValue ||
+            updateDto.SuspendedAt.HasValue ||
+            updateDto.DeferredAt.HasValue ||
+            updateDto.WorkingTimeMs.HasValue;
+
+        // Handle assignment changes first (with role-based permission validation)
+        if (isAssignmentChangeRequested)
         {
             string? newAssignedUserId;
 
-            // Assignment by email - look up the user ID
-            if (string.IsNullOrEmpty(updateDto.AssignedToEmail))
+            if (updateDto.AssignedToEmail != null)
             {
-                // Empty email means unassign
-                newAssignedUserId = null;
+                // Assignment by email
+                if (string.IsNullOrEmpty(updateDto.AssignedToEmail))
+                {
+                    // Empty email means unassign
+                    newAssignedUserId = null;
+                }
+                else
+                {
+                    // Find user by email
+                    var user = await _userManager.FindByEmailAsync(updateDto.AssignedToEmail);
+                    if (user == null)
+                    {
+                        _logger.LogWarning("User not found for assignment email: {Email}", updateDto.AssignedToEmail);
+                        throw new NotFoundException($"User with email '{updateDto.AssignedToEmail}' not found");
+                    }
+                    newAssignedUserId = user.Id;
+                }
             }
             else
             {
-                // Find user by email
-                var user = await _userManager.FindByEmailAsync(updateDto.AssignedToEmail);
-                if (user == null)
-                {
-                    _logger.LogWarning("User not found for assignment email: {Email}", updateDto.AssignedToEmail);
-                    throw new NotFoundException($"User with email '{updateDto.AssignedToEmail}' not found");
-                }
-                newAssignedUserId = user.Id;
+                // Assignment by user ID (legacy)
+                newAssignedUserId = updateDto.AssignedToUserId;
             }
 
             // Validate assignment permissions if assignment is changing and updatingUserId is provided
             if (existingTask.AssignedToUserId != newAssignedUserId && !string.IsNullOrEmpty(updatingUserId))
             {
-                await ValidateTaskAssignmentPermissionAsync(existingTask.ProjectId, updatingUserId, newAssignedUserId);
+                await ValidateTaskAssignmentPermissionAsync(existingTask.ProjectId, updatingUserId!, newAssignedUserId);
             }
 
+            // Apply the assignment change
             existingTask.AssignedToUserId = newAssignedUserId;
         }
-        else if (updateDto.AssignedToUserId != null && updateDto.AssignedToUserId != existingTask.AssignedToUserId)
+
+        // For non-assignment updates, ensure user is assigned to the task
+        // (This runs AFTER potential assignment changes so self-assignment is considered)
+        if (isNonAssignmentChangeRequested && !string.IsNullOrEmpty(updatingUserId))
         {
-            // Validate assignment permissions if updatingUserId is provided
-            if (!string.IsNullOrEmpty(updatingUserId))
-            {
-                await ValidateTaskAssignmentPermissionAsync(existingTask.ProjectId, updatingUserId, updateDto.AssignedToUserId);
-            }
+            await ValidateTaskAssignmentAsync(taskId, updatingUserId!, "UPDATE");
+        }
 
-            // Assignment by userId (legacy support) - only update if explicitly provided
-            existingTask.AssignedToUserId = updateDto.AssignedToUserId;
+        // Update the task properties
+        if (updateDto.Priority.HasValue)
+        {
+            existingTask.Priority = updateDto.Priority.Value;
         }
 
         if (updateDto.Status.HasValue)
@@ -661,4 +674,4 @@ private async Task<bool> ValidateTaskAssignmentAsync(int taskId, string userId,
     }
 
     #endregion
-}
\ No newline at end of file
+}