diff --git a/ui/server.py b/ui/server.py
index 61bc7f4d..34302cd1 100644
--- a/ui/server.py
+++ b/ui/server.py
@@ -85,9 +85,9 @@ def read_root():
 @app.get('/ping') # Get server and optionally session status.
 def ping(session_id:str=None):
     if not task_manager.render_thread.is_alive(): # Render thread is dead.
-        if task_manager.current_state_error: raise HTTPException(status_code=500, detail=str(current_state_error))
+        if task_manager.current_state_error: raise HTTPException(status_code=500, detail=str(task_manager.current_state_error))
         raise HTTPException(status_code=500, detail='Render thread is dead.')
-    if task_manager.current_state_error and not isinstance(task_manager.current_state_error, StopAsyncIteration): raise HTTPException(status_code=500, detail=str(current_state_error))
+    if task_manager.current_state_error and not isinstance(task_manager.current_state_error, StopAsyncIteration): raise HTTPException(status_code=500, detail=str(task_manager.current_state_error))
     # Alive
     response = {'status': str(task_manager.current_state)}
     if session_id: