Errors

Error message format

Encountered an error and looking for answers? You've come to the right place.

This section is a work in progress and not yet complete. If you would like to help us document errors in Aurelia, we welcome all contributions.

Coded error in Aurelia comes with format: AURxxxx:yyyy where:

• AUR is the prefix to indicate it's an error from Aurelia

• xxxx is the code

• : is the delimiter between the prefix, code and the dynamic information associated with the error

• yyyy is the extra information, or parameters related to the error

Enabling development debug information enhancement

When using the production build of the core Aurelia packages, you'll get some error message that looks like this AUR0015:abcxyz, which may not help much during development. If you wish to have better information with regards to an issue you are facing, you can use the development build. To configure your bundler/dev server to pick development build:

Vite

Our @aurelia/vite-plugin will automatically pick the development build when process.env.NODE_ENV is not production. It can also be overriden using useDev property option, like the following example:

import { defineConfig } from 'vite';
import aurelia from '@aurelia/plugin-vite';

export default defineConfig({
    ...,
    plugins: [
        aurelia({ useDev: true })
    ]
})

Webpack

Add alias to the resolve.alias in your webpack config in webpack.config.js, like the scaffolding template at https://github.com/aurelia/new/blob/06f06862bab5f7b13107237a69cf59de1385d126/webpack/webpack.config.js#L117-L123

Others bundlers/dev server

The dist folder of an Aurelia core package looks like this:

dist
  |
  + -> cjs
  |     |
  |     + -> index.cjs
  |     + -> index.dev.cjs
  |
  + -> esm
        |
        + -> index.mjs
        + -> index.dev.mjs

Whenever there's a request to retrieve dist/esm/index.mjs, you can redirect it to dist/esm/index.dev.mjs.

Error list

The section below will list errors by their prefix, and code and give a corresponding explanation, and a way to fix them.

Dependency Injection Errors (from 0001 to 0015)

Dependency Injection errors can be found here.

Template Compiler Errors (From 701-749)

Error Code	Description
AUR0701	This happens when a template has a single template element in your template, and it has as-local-element attribute on it
AUR0702	This happens when a template has one or more attributes that are supposed to be unique on its surrogate elements
AUR0703	This happens when a template controller attribute is used on a surrogate element of a template
AUR0704	This happens when an attribute on a <let/> element is used without .bind or .to-view command
AUR0705	This happens when enhancing a template with one or more element in it already have a class au on it
AUR0706	This happens when [au-slot] attribute is used on an element that is not an immediate child of a custom element
AUR0707	This happens when the template compiler encounters binding to a non-bindable property of a custom attribute
AUR0708	This happens when the template of a custom element has nothing beside template elements with as-local-element
AUR0709	This happens when an as-local-element template is not defined as an immediate child of the root of a custom element template
AUR0710	This happens when an as-local-element template has a <bindable> element inside its template, that is not not an immediate child of its fragment
AUR0711	This happens when a <bindable> inside an as-local-element template does not have a valid property attribute on it
AUR0712	This happens when an as-local-element template has 2 or more <bindable> elements with non-unique attribute or property attributes
AUR0713	This happens when an unknown binding command is encountered in a custom element template
AUR0714	This happens when a custom element or attribute definition has more than 1 primary bindable property
AUR0715	This happens when an as-local-template template has the value of as-local-template as an empty string
AUR0716	This happens when a custom element has 2 or more local elements with the same name

Templating Errors (From 750-800)

Error Code	Description
AUR0750	This happens when there is a binding that looks like this view.ref="...". This likely comes from a v1 template migration.
AUR0751	This happens when there is a ref binding in the template that does not have matching target. Most likely a custom attribute reference
AUR0752	This happens when a controller renders a custom element instruction that it doesn't have a registration. Normally happens in hand-crafted definition
AUR0753	This happens when a controller renders a custom attribute instruction that it doesn't have a registration. Normally happens in hand-crafted definition
AUR0754	This happens when a controller renders a template controller instruction that it doesn't have a registration. Normally happens in hand-crafted definition
AUR0755	This happens when a view factory provider tries to resolve but does not have a view factory associated
AUR0756	This happens when a view factory provider tries to resolve but the view factory associated does not have a valid name
AUR0757	This happens when IRendering.render is called with different number of targets and instructions
AUR0758	This happens when BindingCommand.getDefinition is called on a class/object without any binding command metadata associated
AUR0759	This happens when CustomAttribute.getDefinition is called on a class/object without any custom attribute metadata associated
AUR0760	This happens when CustomElement.getDefinition is called on a class/object without any custom element metadata associated
AUR0761	This happens when CustomElementDefinition.create is called with a string as first parameter
AUR0762	This happens when CustomElement.for is called on an element that does not have any custom element with a given name, without searching in ancestor elements
AUR0763	This happens when CustomElement.for is called and Aurelia isn't able to find any custom element with the given name in the given element, or its ancestors
AUR0764	This happens when CustomElement.for is called on an element with a given name, and Aurelia is unable to find any custom element in the given the element, or its ancestors
AUR0765	This happens when CustomElement.for is called on an element without a given name, and Aurelia is unable to find any custom element in the given element, or its ancestors
AUR0766	This happens when @processContent is called with a string as its first parameter, and Aurelia couldn't find the method on the decorated class
AUR0767	This happens when root property on an Aurelia instance is access before at least one application has been started with this Aurelia instance
AUR0768	This happens when a new Aurelia is created with a predefined container that already has IAurelia registration in it, or its ancestors
AUR0769	This happens when an Aurelia application is started with a document fragment before it's adopted by a document
AUR0770	This happens when Aurelia.prototype.start is called with a null/undefined value as the first parameter
AUR0771	This happens when Aurelia.prototype.dispose is called before the instance is stopped
AUR0772	This happens when the @watch decorator is used without a valid first parameter
AUR0773	This happens when the @watch decorator is used and Aurelia is not able to resolve the first parameter to a function
AUR0774	This happens when the @watch decorator is used on a class property instead of a method

HTML observation errors

Error Code	Description
AUR0651	This happens when the binding created .attr binding command is forced into two way mode against any attribute other than class/style
AUR0652	This happens when the default NodeObserverLocator.getObserver is called with an object and property combo that it doesn't know how to observe, and dirty checking is disabled
AUR0653	This happens when NodeObserverLocator property->observation events mapping is getting overridden
AUR0654	This happens when a <select> element is specified multiple, but the binding value is not an array

Controller errors

Error Code	Description
AUR0500	This happens when Controller.getCachedOrThrow throws
AUR0501	This happens when a custom element is specified containerless and has <slot> element in its template
AUR0502	This happens when a disposed controller is being activated
AUR0503	This happens when the internal state of a controller is corrputed during activation
AUR0504	This happens when a synthetic view is activated without a proper scope
AUR0505	This happens when the internal state of a controller is coruppted during deactivation
AUR0506	This happens when Aurelia fails to resolve a function from the first parameter of a @watch decorator

Default resources errors

Error Code	Description
AUR0801	This happens when & self binding behavior is used on non-event binding
AUR0802	This happens when & updateTrigger binding behavior is used without any arguments
AUR0803	This happens when & updateTrigger binding behavior is used on binding without view -> view model observation
AUR0804	This happens when & updateTrigger binding behavior is used on binding that does not target a DOM element
AUR0805	This happens when <au-compose> scopeBehavior property is assigned a value that is not either auto or scoped
AUR0806	This happens when <au-compose> component binding is used with a custom element with containerless = true
AUR0807	This happens when there's a corrupted internal state of <au-compose> and activation is called twice
AUR0808	This happens when there's a corrupted internal state of <au-compose> and deactivation is called twice
AUR0809	This happens when <au-render> component binding is given a string value, and there's no custom element with matching name
AUR0810	This happens when else attribute does not follow an if attribute
AUR0811	This happens when portal attribute is a given an empty string as CSS selector fortarget, and strict mode is on
AUR0812	This happens when portal attribute couldn't find the target element to portal to, and strict mode is on
AUR0813	This happens when then/catch/pending attributes is used outside of a promise attribute
AUR0814	This happens when the internal of the repeat attribute get into a race condition and is corrupted
AUR0815	This happens when case/default-case attributes is used outside of a switch attribute
AUR0816	This happens when there are multiple default-case attributes inside a switch attribute
AUR0817	This happens when & signal binding behavior is used on binding that does not have handleChange method
AUR0818	This happens when & signal binding behavior is used without a valid name (non empty)

Plugin errors

Error Code	Plugin name	Description
AUR0901	Dialog	This happens when an application is closed with some dialogs still open
AUR0903	Dialog	This happens when IDialogService.open is called without both component and template property
AUR0904	Dialog	This happens when the default configuration of the dialog plugin is used, as there's no registration associated for key interfaces

Runtime module

AST errors (from 101 to 150)

Error Code	Description
AUR0101	This happens when Aurelia couldn't find a binding behavior specified in an expression
AUR0102	This happens when there are two binding behaviors with the same name in an expression
AUR0103	This happens when a value converter for a given name couldn't be found during the evaluation of an expression
AUR0104	This happens when a value converter for a given name couldn't be found during the assignment of an expression
AUR0105	This happens when the special $host contextual property is accessed but no thing is found in the scope tree
AUR0106	This happens when an expression looks like this $host = ..., as $host is a readonly property
AUR0107	This happens when a call expression is evaluated but the object evaluated by the expression isn't a function
AUR0108	This happens when a binary expression is evaluated with an unknown operator
AUR0109	This happens when an unary expression is evaluated with an unknown operator
AUR0110	This happens when a tagged template (function call) is but the function specified isn't a function
AUR0111	This happens when a function call AST is evaluated but no function is found
AUR0112	This happens when a non-object or non-array value is assigned for destructured declaration for a repeat.for statement
AUR0113	This happens when an increment operator is used outside of an event handler

Parser errors (from 151-200)

Error Code	Description
AUR0151	An expression has an invalid character at the start
AUR0152	An expression has .. or ...
AUR0153	The parser encounters an unexpected identifier in an expression
AUR0154	The parser encounters an invalid AccessMember expression
AUR0155	The parers encounters an unexpected end in an expression
AUR0156	The parser encounters an unconsumable token in an expression
AUR0158	The expression has an invalid assignment
AUR0159	An expression has no valid identifier after the value converter ` | ` symbol
AUR0160	An expression has no valid identifier after the binding behavior & symbol
AUR0161	The parser encounters an invalid of keyword
AUR0162	The parser encounters an unconsumed token
AUR0163	The parser encounters an invalid binding identifier at left hand side of an of keyword
AUR0164	The parser encounters a literal object with a property declaration that it doesn't understand
AUR0165	An expression has an opening string quote ' or ", but no matching ending quote
AUR0166	An expression has an opening template string quote ```, but has no matching end
AUR0167	The parser encounters an unexpected token
AUR0168	The parser encounters an unexpected character
AUR0169	The parser encounters an unexpected character while parsing destructuring assignment expression

Others (from 200-300)

Error Code	Description
AUR0201	BindingBehavior.getDefinition is called on a class/object without any binding behavior metadata associated
AUR0202	ValueConverter.getDefinition is called on a class/object without any value converter metadata associated
AUR0203	BindingContext.get is called with null/undefined as the first parameter
AUR0204	Scope.fromOverride is called with null/undefined as the first parameter
AUR0205	Scope.fromParent is called with null/undefined as the first parameter
AUR0206	ConnectableSwitcher.enter is called with null/undefined as the first parameter
AUR0207	ConnectableSwitcher.enter is called with the currently active connectable
AUR0208	ConnectableSwitcher.exit is called with null/undefined as the first parameter
AUR0209	ConnectableSwitcher.exit is called with an inactive connectable
AUR0210	getCollectionObserver is called with an not-supported collection type
AUR0211	a binding subscried to an observer, but does not implement method handleChange
AUR0212	a binding subscribed to a collection observer, but does not implement method handleCollectionChange
AUR0220	a Set/Map size observer .setValue method is called
AUR0221	the setValue method on a computed property without a setter
AUR0222	Aurelia doesn't know how to observe a property on an object, and dirty checking is disabled
AUR0224	Encounters an invalid usage of @observable
AUR0225	An effect is attempted to run again, after it has stopped
AUR0226	An effect has reach its limit of recursive update

Router-Lite

Router-Lite logs various events. Majority of those events are traces. The non-warn, non-error events are not logged in non-dev build, and are only available for troubleshooting in the dev-build. This section only lists the error codes.

Error Code	Description
AUR3155	The route context cannot be resolved from the given DOM node. This happens if the given node is not a custom element or not a child-node of a custom element.
AUR3166	This happens when an attempt to eagerly (without involving the route recognizer) recognize a routing instruction failed. If you are getting this error, please report it.
AUR3167	This happens when the application root is not yet set, but the router is trying to set a routing root. If you are getting this error, please report it.
AUR3168	This happens when a route context already exist for the application root; for example if it attempted to set the routing root more than once.
AUR3169	This happens when no controller exists for the application root. If you are getting this error, please report it.
AUR3170	A route context cannot be resolved for the given input.
AUR3171	This happens when the route node of the route context is not set. If you are getting this error, please report it.
AUR3172	This happens when the viewport agent of the route context is not set. If you are getting this error, please report it.
AUR3173	This happens the import() function is used as component, while configuring a route, but no path has been specified. This is not supported.
AUR3174	No viewport agent can be resolved for a given request.
AUR3175	This happens the import() function is used as component, while configuring a route, but the module does not export any aurelia custom element.
AUR3270	A routing transition failed.
AUR3271	The routing context of the router is not set. If you are getting this error, please report it.
AUR3350	Activation of component from a viewport failed due to incorrect state. If you are getting this error, please report it.
AUR3351	Deactivation of component from a viewport failed due to incorrect state. If you are getting this error, please report it.
AUR3352	The state of the viewport agent is not as expected. If you are getting this error, please report it.
AUR3353	The transition was either erred or cancelled via one of the can* hooks, but the router attempts to continue with the current instruction instead of cancelling it. If you are getting this error, please report it.
AUR3400	A navigation instruction cannot be created.
AUR3401	Neither the given routing instruction can be recognized, nor a fallback is configured.
AUR3401	The redirect route cannot be recognized.
AUR3403	toUrlComponent is invoked on a navigation instruction with incompatible type. This happens when the type of the instruction is a promise or a view-model.
AUR3450	Thrown by the navigation model when the endpoint for a path is not found.
AUR3500	Thrown by the route expression parser upon encountering an unexpected segment.
AUR3501	Thrown by the route expression parser when all of the given input string cannot be consumed.
AUR3502	Thrown if an unexpected segment is encountered during migrating parameters for redirect route.
AUR3550	Thrown when a re-attempt is made to call the getRouteConfig hook for the same component. If you are getting this error, please report it.
AUR3551	A custom element definition could not be resolved from the given string name, as no route context was provided. If you are getting this error, please report it.
AUR3552	A custom element definition could not be resolved from the given string name, as it is potentially not a custom element.
AUR3553	A custom element definition could not be resolved from theimport() function, as no route context was provided to resolve it.
AUR3554	The validation of a route config failed due to unexpected type of property.
AUR3555	The validation of a route config failed, as the config is either undefined or null.
AUR3556	The validation of a route config failed due to unexpected property.
AUR3556	The validation of a redirect route config failed due to unexpected property.