Preview didn't load
The app failed to start in the preview

The page loaded but the React app never mounted within 8 seconds.

Try these fixes
  1. Hard-reload the preview (Cmd/Ctrl + Shift + R)
  2. Open the browser console and copy any red errors back to chat
  3. If you just edited code, check for a syntax error in the last changed file
  4. Try Restore in History to roll back to the previous working version
Route: — React error boundary triggered
Technical details
React error

            

          

          

        



        

          
          
          
        

        

      

    


    
    

      

        

          

          App not responding
        

        
The page loaded but stopped updating

        

          We haven't seen activity from the app in over 12 seconds. It may be stuck in a render loop or blocked on a long task.
        

        

          
            Route: —
          
        

        

          
Try these fixes

          
    
            
  1. Check the console for repeated warnings (infinite render loop)
    2. 
            
  2. Look for a useEffect missing its dependency array
    3. 
            
  3. Inspect recent edits for setState calls inside render
    4. 
            
  4. Reload — if it recurs immediately, revert via History
    5.