ErrLookup › dotnet/aspnetcore
dotnet/aspnetcore
ASP.NET Core is a cross-platform .NET framework for building modern cloud-based web applications on Windows, Mac, or Linux. · C# · 7,068 source files
Analyzed at 3600ca084e on 2026-08-11. 296 documented errors.
| Code / Message | Type | Severity | Tags |
|---|---|---|---|
| The frame at index is of type ' ', not ' '. | exception | error | blazor, render-tree, renderframe, invalidoperationexception |
| Component parameters may only be added immediately after… | exception | error | blazor, render-tree, renderfragment, invalidoperationexception |
| Render output is invalid for component of type | exception | critical | blazor, render-tree, renderfragment, unclosed-frame, invalidoperationexception |
| Byte array index ' ' does not exist. | exception | error | js-interop, blazor, byte-array, serialization, reviver, protocol |
| End of component comment must have a value for the… | exception | error | blazor, ssr, prerendering, component-markers, malformed-payload |
| Cannot merge mismatching component descriptors | exception | error | blazor, root-components, render-mode, component-markers, merge |
| Enhanced navigation does not support making a non-GET… | exception | error | blazor, enhanced-navigation, forms, redirect, cors, external-origin |
| The registered callback | exception | error | blazor, render-mode, persistence, multi-store |
| Cannot update existing state: previous state has not been… | exception | error | blazor, persistent-state, restore, lifecycle |
| Enhanced navigation does not support making a non-GET… | exception | error | blazor, enhanced-navigation, forms, non-blazor-endpoint, http-headers |
| errorMessage | validation | error | protocol, json, validation, parsing, message-type |
| Unable to set property | exception | error | blazor, parameters, reflection, binding |
| A public property ' ' on component type ' ' with a public… | exception | error | blazor, persistent-state, reflection, value-provider |
| Renderer with ID ' ' is not listening for navigation events | exception | error | blazor, navigation, renderer, interop, initialization-order |
| There are no content providers with the given section ID | exception | error | blazor, components, sections, lifecycle, invalidoperation |
| State already persisted. | exception | error | blazor, persistent-state, persistence, lifecycle |
| Cannot connect component | exception | error | blazor-custom-elements, lifecycle, dom, disposal |
| The URI ' ' is not contained by the base URI ' '. | exception | error | blazor, routing, uri, configuration |
| No enhanced programmatic navigation handler has been… | exception | error | blazor, navigation, enhanced-navigation, handler, initialization |
| Object of type ' ' has a property matching the name ' '… | exception | error | blazor, parameters, reflection, attributes |
| The value must implement | exception | error | blazor, routing, routedata, icomponent, argumentexception |
| Render mode already set. | exception | error | blazor, render-mode, persistent-state, configuration |
| Cannot handle type class | exception | error | java, signalr, reflection, types, binding |
| The type does not implement . | exception | error | blazor, routing, router, navigation, icomponent, invalidoperationexception |
| State already initialized. | exception | error | blazor, persistent-state, restore, lifecycle |
| The property ' ' on component type ' ' cannot be set… | exception | error | blazor, parameters, cascading-values, binding |
| Unexpected message type | exception | error | java, signalr, messagepack, serialization, protocol |
| Failed to retrieve token, no account found. | exception | error | blazor, wasm, authentication, msal, token, no-account |
| The following routes are ambiguous | exception | error | blazor, routing, ambiguous-routes, routetablefactory, invalidoperationexception |
| EqualTo validator requires a non-empty "other" parameter. | exception | error | blazor, validation, equalto, form-validation, misconfiguration |
| JS object instance with Id | exception | error | js-interop, blazor, object-reference, disposed, serialization, reviver |
| The workspace path was not provided. | exception | error | nodejs, npm, build, arguments, bug |
| There are no callbacks registered for the method | exception | error | signalr, java, binding, handler, internal-invariant |
| Dynamic root components have already been enabled. | exception | critical | blazor, root-components, multi-host, configuration |
| Scopes not granted. | exception | error | blazor, wasm, authentication, msal, token, consent, scopes |
| The method cannot be used as an event handler because it… | exception | error | blazor, events, event-handler, reflection |
| Unknown parameter | exception | error | blazor, sections, sectioncontent, parameters, argumentexception |
| Message is incomplete. | exception | error | signalr, typescript, protocol, framing, transport |
| The static asset ' ' is already mapped to . | exception | error | blazor, static-assets, resource-asset, startup, invalidoperationexception |
| Invalid payload for Ack message. | exception | error | signalr, messagepack, ack, reliable-stream, invariant |
| There is no file with ID | exception | error | input-file, interop, blazor, file-upload, lifecycle |
| Cannot perform enhanced form submission that changes the… | exception | error | blazor, enhanced-navigation, forms, history, post-redirect-get |
| HttpConnection.stopConnection | exception | error | state-machine, transport, connection-lifecycle, race-condition |
| No component found for route | exception | error | blazor, routing, router, render-by-route, invalidoperationexception |
| The type ' ' declares a property matching the name ' ' that… | exception | error | blazor, persistent-state, reflection, services |
| The ' ' argument is required. | validation | error | signalr, typescript, argument-validation, precondition |
| Setting and properties simultaneously is not supported. Use… | exception | error | blazor, routing, router, notfound, configuration, invalidoperationexception |
| The property ' ' on component type ' ' cannot be set… | exception | error | blazor, parameters, capture-unmatched, binding |
| Binary protocols over XmlHttpRequest not implementing… | exception | error | transport, long-polling, binary, browser, legacy |
| requires that ' ' and ' ' cannot both have non-null values. | exception | error | blazor, sections, sectioncontent, configuration, invalidoperationexception |
| Object of type ' ' does not have a property matching the… | exception | error | blazor, parameters, reflection, binding |
| Could not load settings from | exception | error | blazor, wasm, authentication, oidc, configuration, network, startup |
| The message type is not supported yet. | exception | error | signalr, java, protocol, message-type, streaming |
| Unable to focus an invalid element. | exception | error | dom, focus, interop, blazor, element-ref |
| Some passkey features are missing. Please update your… | exception | warning | browser-support, passkey, webauthn, feature-detection, blazor |
| Multiple properties were found on component type | exception | error | blazor, parameters, capture-unmatched, reflection |
| The component requires a non-null value for the parameter . | exception | error | blazor, routing, routeview, parameter, invalidoperationexception |
| Unable to find the provided template | exception | error | blazor, routing, route-template, routetablefactory, invalidoperationexception |
| Error writing MessagePack data. | exception | error | java, signalr, messagepack, serialization, jackson |
| HubConnection trying to negotiate when not in the… | exception | error | signalr, java, state-machine, race, connection-lifecycle |
| The type ' ' declares a parameter matching the name ' '… | exception | error | blazor, parameters, reflection, binding |
| The event ' ' is already registered. | validation | error | blazor, events, registration, duplicate |
| The property ' ' on component type ' ' cannot be used with… | exception | error | blazor, parameters, capture-unmatched, reflection |
| Descriptors must be assigned a renderer ID before getting… | exception | error | blazor, root-components, renderer-id, internal-invariant, initialization |
| The required antiforgery form field | validation | error | antiforgery, aspnetcore, security, csrf, validation |
| The type ' ' declares more than one parameter matching the… | exception | error | blazor, parameters, reflection, naming |
| Unknown type ' ' for parameter | exception | error | blazor-custom-elements, attribute-parsing, type-mismatch, registration |
| Only one interactive runtime may enable navigation… | exception | error | blazor, navigation, router, render-mode, multiple-runtimes |
| The component requires a value for the parameter . | exception | error | blazor, routing, router, configuration, renderfragment, invalidoperationexception |
| The property ' ' on component type ' ' cannot be set using… | exception | error | blazor, parameters, cascading-values, binding |
| End of component comment prerendered property must match… | exception | error | blazor, ssr, prerendering, component-markers, desync |
| Could not resolve a root component with SSR component ID | exception | error | blazor, root-components, ssr, component-id, dom-mutation |
| Circuit host not initialized. | exception | critical | circuit, persisted-state, signalr, lifecycle, blazor-server |
| To support navigation locks | exception | error | blazor, routing, navigation-lock, extensibility |
| Worker .NET runtime not loaded | exception | critical | web-worker, blazor, wasm, initialization, race-condition |
| Cannot supply a component of type | exception | error | blazor, render-mode, interactivity, host-configuration, di |
| Invalid payload. | exception | error | protocol, json, parsing, message-type |
| The event handler parameter type | exception | error | blazor, events, event-handler, reflection |
| Cannot format query parameters with values of type | exception | error | blazor, querystring, type-conversion, uri |
| Failed to download after attempts. | exception | error | python, network, retry, debian, cross-build |
| Invalid JS call result type | exception | error | js-interop, blazor, serialization, version-mismatch, protocol |
| Cannot start a disposed circuit. | exception | error | circuit, lifecycle, blazor-server, signalr, dispose |
| Invalid payload for Sequence message. | exception | error | signalr, messagepack, sequence, reliable-stream, invariant |
| Negotiate redirection limit exceeded. | exception | error | signalr, java, network, negotiate, redirect, configuration |
| Negotiation can only be skipped when using the WebSocket… | validation | error | negotiation, transport, configuration, websocket |
| The options parameter is required. | validation | error | events, registration, interop, argument-validation, blazor |
| Invalid headers. | exception | error | messagepack, protocol, version-mismatch, serialization |
| Root components cannot be marked as interactive. The | exception | critical | blazor, prerendering, markers, ssr, document-root |
| TypeReference must be instantiated with a type parameter… | exception | error | signalr, java, generics, typereference, api-misuse |
| Found malformed component comment at | exception | error | blazor, prerendering, markers, html, ssr |
| Unexpected renderer ID | exception | error | blazor, root-components, renderer-id, version-skew, persisted-state |
| The circuit associated with this dispatcher is no longer… | exception | error | circuit, interop, dispose, dispatcher, blazor-server |
| There were no compatible transports on the server. | exception | error | signalr, java, negotiate, transport, websocket, network |
| Invalid payload for Completion message. | exception | error | protocol, json, parsing, message-type |
| Cannot create a JSStreamReference from the value | exception | error | js-interop, blazor, stream, object-reference, serialization |
| Expected either 'error' or 'result' to be provided, but not… | validation | error | signalr, java, protocol, completion-message, invariant |
| Failed to download , Status Code | exception | error | python, network, http, debian, cross-build |
| Unknown transport: . | validation | error | transport, configuration, enum, typescript |
| The HubConnection failed to transition from the | exception | error | signalr, java, state-machine, concurrency, lifecycle |
| Error reading MessagePack data. | exception | error | signalr, java, messagepack, protocol, serialization, parsing |