ErrLookup › pallets/flask
pallets/flask
The Python micro framework for building web applications. · Python · 24 source files
Analyzed at 3596b1ab61 on 2026-08-11. 54 documented errors.
| Code / Message | Type | Severity | Tags |
|---|---|---|---|
| The factory in module could not be called with the… | exception | error | flask, cli, app-factory, configuration |
| A valid Flask application was not obtained from | exception | error | flask, cli, app-resolution, configuration |
| Object of type is not JSON serializable | exception | error | flask, json, serialization |
| Session backend did not open a session. | exception | error | flask, testing, session, secret-key, configuration |
| You tried to access the file | exception | warning | flask, file-upload, forms, debug, http |
| The setup method ' ' can no longer be called on the… | exception | error | flask, lifecycle, setup, assertion, configuration |
| {template} | exception | error | flask, templating, jinja2, template-not-found, configuration |
| While importing , an ImportError was raised:\n\n | exception | error | flask, cli, import, dependencies |
| 'stream_with_context' can only be used when a request… | exception | error | flask, streaming, request-context, lifecycle |
| The setup method ' ' can no longer be called on the… | exception | error | flask, blueprint, lifecycle, assertion, configuration |
| There is no request in this context. | exception | error | flask, request-context, lifecycle |
| app.json.response() takes either args or kwargs, not both | exception | error | flask, json, api-contract |
| 'view_func' name may not contain a dot '.' character. | exception | error | flask, blueprint, endpoint, view-func, validation |
| No root path can be found for the provided module | exception | error | flask, packaging, namespace-package, configuration |
| If an instance path is provided it must be absolute. A… | exception | error | flask, configuration, filesystem, paths |
| 'after_this_request' can only be used when a request… | exception | error | flask, request-context, lifecycle |
| Could not locate a Flask application. Use the 'flask --app'… | exception | error | flask, cli, app-resolution, configuration, environment |
| Cannot pop this context | exception | error | flask, context, concurrency, lifecycle |
| The session is unavailable because no secret key was set. … | exception | error | flask, session, secret-key, security, configuration |
| A request was sent to | exception | warning | routing, debug, forms, redirect |
| The environment variable | exception | error | flask, config, environment, configuration |
| ' ' is not a subclass of Exception. Handlers can only be… | exception | error | flask, error-handler, validation, exception |
| The name ' ' is already registered for blueprint . Use… | exception | error | flask, blueprint, registration, duplicate, naming |
| Allowed methods must be a list of strings, for example… | exception | error | flask, routing, type-error, methods, configuration |
| 'copy_current_request_context' can only be used when a… | exception | error | flask, request-context, concurrency, lifecycle |
| ' ' is not a recognized HTTP error code. Use a subclass of… | exception | error | flask, error-handler, http, validation |
| is an instance, not a class. Handlers can only be… | exception | error | flask, error-handler, type-error, validation |
| 'static_folder' must be set to serve static_files. | exception | error | static-files, configuration, runtime-error |
| Cookies are disabled. Create a client with… | exception | error | flask, testing, session, client, cookies |
| 'endpoint' may not contain a dot '.' character. | exception | error | flask, blueprint, endpoint, validation, naming |
| Tag ' ' is already registered. | exception | error | flask, session, json, serialization, configuration |
| View function mapping is overwriting an existing endpoint… | exception | error | flask, routing, endpoint, assertion, duplicate |
| Cannot pop this context | exception | error | flask, context, lifecycle, resource-management |
| Use the 'route' decorator to use the 'methods' argument. | exception | error | flask, routing, type-error, methods, decorator |
| 'name' may not contain a dot '.' character. | exception | error | flask, blueprint, validation, naming |
| Cannot pop this context | exception | error | flask, context, lifecycle, resource-management |
| Function reference must be a simple name | exception | error | cli, flask-app-env, parsing |
| \nThe view function did not return a valid response. The… | exception | error | view, response, wsgi, type-error |
| Unable to build URLs outside an active request without… | exception | error | url-building, configuration, context |
| Detected factory ' ' in module ' ', but could not call it… | exception | error | cli, factory, flask-app-env |
| Could not import . | exception | error | flask, cli, import, configuration |
| The view function did not return a valid response tuple… | exception | error | view, response, type-error |
| Resources can only be opened for reading. | exception | error | resources, io, value-error |
| When specifying '_scheme', '_external' must be True. | exception | error | url-building, value-error, configuration |
| 'name' may not be empty. | exception | error | flask, blueprint, validation, configuration |
| Install Flask with the 'async' extra in order to use async… | exception | error | async, dependencies, runtime-error |
| Cannot register a blueprint on itself | exception | error | flask, blueprint, validation, recursion |
| The view function for | exception | error | view, response, type-error |
| Failed to parse arguments as literal values | exception | error | cli, flask-app-env, parsing |
| Detected multiple Flask applications in module | exception | error | cli, configuration, flask-app-env |
| Failed to find Flask application or factory in module | exception | error | cli, flask-app-env, discovery |
| The view function did not return a valid response. The… | exception | error | view, response, type-error |
| Failed to parse as an attribute name or function call. | exception | error | cli, flask-app-env, parsing |
| Failed to find attribute | exception | error | cli, flask-app-env, discovery |