weird new flask assertion error forbidding endpoint declaration decorators

app.py

@@ -751,11 +751,6 @@ def make_view(response_list=[]):
     else:
         response = jsonify(response_list)
 
-
-@app.get("/fe")
-def frontend():
-    return send_file('kjv_fe.html')
-
 @app.get("/search") # user-facing keyword search. To be moved to backend, possibly replaced with semantic search.
 def search():
     keywords = request.args.get("kw", None)