python - Flask custom error page 500 not working -

i have following code in __init__.py

@app.errorhandler(404) def page_not_found(e):     return render_template('404.html'), 404  @app.errorhandler(500) def internal_server_error(e):     return render_template('500.html'), 500  @app.errorhandler(403) def page_forbidden(e):     return render_template('403.html'), 500 

it used catch 500 errors , show nice 500.html template. moved views separate blueprint files , 500 errorhandler not work. handler though. 404 works fine.

if server throws 500 error, display default chrome internal server error message , not template. did wrong when created blueprints create issue?

here entire __init__.py file

import datetime import mysql.connector import os flask import flask, render_template, session, request, blueprint flask.ext.moment import moment flask.ext.login import loginmanager db_classes import user  info import info_blueprint claims import claims_blueprint users import users_blueprint members import members_blueprint drug import drug_blueprint auth import auth_blueprint formulary import formulary_blueprint  config import mysql_usr, mysql_host, mysql_pass, mysql_db, mysql_port, second_to_live  decorators import role_required  app = flask(__name__, template_folder="static/templates") app.config.from_object('config')  moment = moment(app)  login_manager = loginmanager() login_manager.init_app(app) login_manager.session_protection = 'strong' login_manager.login_view = 'login'  @login_manager.user_loader def load_user(user_id):     return user.query.get(int(user_id))   #################### #   blueprints ####################  app.register_blueprint(info_blueprint) app.register_blueprint(claims_blueprint) app.register_blueprint(users_blueprint) app.register_blueprint(members_blueprint) app.register_blueprint(drug_blueprint) app.register_blueprint(formulary_blueprint) app.register_blueprint(auth_blueprint)    ##################### #   error routes #####################     @app.errorhandler(404) def page_not_found(e):     return render_template('404.html'), 404  @app.errorhandler(500) def internal_server_error(e):     return render_template('500.html'), 500  @app.errorhandler(403) def page_forbidden(e):     return render_template('403.html'), 500  ##################### #   context processors #####################  @app.before_request def make_session_permanent():     session.permanent = true     app.permanent_session_lifetime = datetime.timedelta(seconds=second_to_live)  @app.context_processor def inject_time():     return dict(current_time=datetime.datetime.utcnow())  if __name__ == "__main__":     app.run(host= '0.0.0.0', debug=true) 

something didn't realize... flask docs

please note if add error handler “500 internal server error”, flask not trigger if it’s running in debug mode.