# Error Codes and Messages
The LWC compiler uses parsers such as Babel for JavaScript/TypeScript, a CSS parser for stylesheets, and a template parser for HTML to transform component code. The compiler provides diagnostics related to component structure and syntax. Some of the LWC error codes are wrappers around these parser errors.
LWC returns error codes that use the format LWC0000: Error message. These error codes can either be an error at compile time or a warning at run time. An error is blocking and stops compilation. You can observe these errors in the terminal or CLI output. A warning is a non-blocking diagnostic that doesn't affect compilation. You can typically observe these warnings in the browser's web console.
| Error Code | Description | Severity Level |
|---|---|---|
| LWC1001 | Represents a generic, unexpected compilation error in the LWC compiler. | Error |
| LWC1002 | Represents a warning in module resolution. | Warning |
| LWC1005 | Represents an unsupported file extension error. | Error |
| LWC1006 | Represents a source type error on transform() or transformSync(). |
Error |
| LWC1007 | Represents a JavaScript transformer error caused by a syntax error. | Error |
| LWC1009 | Represents a CSS transformer error when processing CSS stylesheet files. | Error |
| LWC1011 | Represents an import path error. | Error |
| LWC1016 | Raised when a Lightning web component tries to assign a value to a getter, which is not permitted. | Error |
| LWC1021 | Represents an error for an invalid outputConfig.sourcemap value. |
Error |
| LWC1023 | Represents an error on the options object. | Error |
| LWC1024 | Represents a file content error. | Error |
| LWC1027 | Represents an error that's thrown when a string is expected for an ID. | Error |
| LWC1028 | Represents a template compiler error when the configuration parameter is not an object. | Error |
| LWC1030 | Represents an unrecognized property error on the template compiler. | Error |
| LWC1034 | Represents an error for an ambiguous attribute value. | Error |
| LWC1035 | Represents an ambiguous attribute value error in the template compiler. | Error |
| LWC1036 | Represents an error for a boolean attribute that's incorrectly set. | Error |
| LWC1037 | Represents a boolean attribute value error. | Error |
| LWC1038 | Represents a computed property access error in a template expression. | Error |
| LWC1039 | Represents an iterator directive error. | Error |
| LWC1040 | Represents an id value whitespace error. |
Error |
| LWC1041 | Represents a static id value error. |
Error |
| LWC1042 | Represents a duplicate id value error. |
Error |
| LWC1043 | Represents an attribute error on an event handler. | Error |
| LWC1044 | Represents an error that's caused by using the for:each or for:item directive without the other. |
Error |
| LWC1045 | Represents a literal value error on a for:each directive. |
Error |
| LWC1046 | Represents a value error on the for:index directive. |
Error |
| LWC1047 | Represents a value error on the for:item directive. |
Error |
| LWC1048 | Represents an error that occurs when the srcdoc attribute is used on an iframe. |
Error |
| LWC1049 | Represents an SVG tag error in the <svg> namespace. |
Error |
| LWC1050 | Represents an invalid MathML tag error. | Error |
| LWC1051 | Represents a forbidden template tag error. | Error |
| LWC1052 | Represents an unexpected error during template compilation. | Error |
| LWC1054 | Represents an error that occurs when the if:* directive is assigned to a string literal or has no value. |
Error |
| LWC1055 | Represents a case error in HTML attribute names. | Error |
| LWC1056 | Represents a naming error on an event handler attribute. | Error |
| LWC1057 | Represents a warning when an invalid attribute is used on an HTML element. | Warning |
| LWC1058 | Represents an invalid HTML syntax error. | Error |
| LWC1063 | Represents an is attribute error. |
Error |
| LWC1064 | Represents a key attribute error. |
Error |
| LWC1065 | Represents an invalid key value on an element. | Error |
| LWC1066 | Represents an invalid key value for an element. | Error |
| LWC1071 | Represents an error for a missing key for an element in an iterator. | Error |
| LWC1072 | Represents an error for a missing root template tag. | Error |
| LWC1074 | Represents an error for an expression that contains a semicolon. | Error |
| LWC1075 | Represents an error for a template that contains more than one root-level node. | Error |
| LWC1076 | Represents an error for a slot name is assigned to a dynamic expression. | Error |
| LWC1077 | Represents an error for a non-root template tag that doesn't contain a directive. | Error |
| LWC1078 | Represents an error for a missing closing tag. | Error |
| LWC1079 | Represents an error for a missing root <template> element. |
Error |
| LWC1080 | Represents an error for an invalid attribute on the root <template> element. |
Error |
| LWC1082 | Represents an error for an invalid template directive on the <slot> element. |
Error |
| LWC1083 | Represents a template parsing error when JavaScript expressions in HTML templates have syntax errors, unbalanced brackets, or other parsing issues. | Error |
| LWC1084 | Represents an invalid modifier on the if: directive. |
Error |
| LWC1085 | Represents an invalid value on the lwc:dom directive. |
Error |
| LWC1086 | Represents an error for a non-empty element with the lwc:dom directive. |
Error |
| LWC1087 | Represents an error for a custom element with the lwc:dom directive. |
Error |
| LWC1088 | Represents an error for an lwc:dom directive on any <slot> element. |
Error |
| LWC1092 | Represents an error for a missing parameter on a wire adapter. | Error |
| LWC1093 | Represents an @api and @track combined usage error. |
Error |
| LWC1094 | Represents an @wire configuration object error. |
Error |
| LWC1095 | Represents an @api and @wire combined use error. |
Error |
| LWC1096 | Represents a duplicate @api property error. |
Error |
| LWC1097 | Represents a wire adapter identifier error. | Error |
| LWC1098 | Represents an error when a @wire decorator's first parameter references a local binding. |
Error |
| LWC1099 | Represents an error on the default value of a boolean public property. | Error |
| LWC1100 | Represents an error for invalid decorator usage. | Error |
| LWC1101 | Represents an error for a decorator applied to a private class member. | Error |
| LWC1102 | Represents an error for a decorator not properly imported from the lwc module. |
Error |
| LWC1105 | Represents an error for multiple @wire decorators on a single method or property. |
Error |
| LWC1106 | Represents an @api error when the decorator is used with the computed property syntax. |
Error |
| LWC1107 | Represents an error for a property name that starts with the "data" prefix. | Error |
| LWC1108 | Represents an error for a property name that starts with the "on" prefix. | Error |
| LWC1109 | Represents an error for a lowercase attribute name that corresponds to a property that uses a camelCase name. | Error |
| LWC1110 | Represents an error for a property name that corresponds to a reserved HTML attribute name. | Error |
| LWC1111 | Represents an error for a property name that corresponds to a future reserved attribute name. | Error |
| LWC1112 | Represents an error for a duplicate @api declaration on a getter and setter. |
Error |
| LWC1113 | Represents an error for a @track decorator that is applied to a class method, getter, or setter. |
Error |
| LWC1116 | Represents an error for an invalid folder name. | Error |
| LWC1121 | Represents an error for an invalid import. | Error |
| LWC1122 | Represents an error for a <style> element inside an LWC component's HTML template. |
Error |
| LWC1123 | Represents a warning for an unknown HTML tag. | Warning |
| LWC1124 | Represents an error for an attribute name in an LWC template starts with an invalid character. | Error |
| LWC1125 | Represents an error for an attribute name in an LWC template that ends with a non-alphanumeric character. | Error |
| LWC1127 | Represents an error for using an invalid lwc: directive on an element in an LWC template. |
Error |
| LWC1128 | Represents an error for using lwc:dynamic without enabling the compiler option. |
Error |
| LWC1129 | Represents an error for using lwc:dynamic on an element that is not a custom element. |
Error |
| LWC1130 | Represents an error for passing a string literal to lwc:dynamic. |
Error |
| LWC1131 | Represents an error when you use computed property syntax to access a wire adapter in the first parameter of the @wire decorator. |
Error |
| LWC1132 | Represents an error that occurs when the @wire identifier contains nested member expressions. |
Error |
| LWC1133 | Represents an error for setting lwc:render-mode to an invalid value. |
Error |
| LWC1134 | Represents an error for invalid attributes on a <slot>element. |
Error |
| LWC1135 | Represents an error for using lwc:dom="manual" on an element inside a Light DOM template. |
Error |
| LWC1136 | Represents an error placing for:each and iterator:* on the same element. |
Error |
| LWC1137 | Represents a warning for defining multiple slots with the same name within the same rendering context. | Warning |
| LWC1138 | Represents a warning for placing slots inside iteration blocks. | Warning |
| LWC1139 | Represents an error for adding an event listener to a <slot> element inside a Light DOM template. |
Error |
| LWC1140 | Represents an error for applying lwc:inner-html to a non-native HTML element. |
Error |
| LWC1141 | Represents an error for using lwc:inner-html on <slot> or <template>. |
Error |
| LWC1143 | Represents an error for an invalid lwc:inner-html usage on an element. |
Error |
| LWC1144 | Represents a warning for invalid HTML nesting. | Warning |
| LWC1149 | Represents a warning for an invalid key attribute. |
Warning |
| LWC1197 | Represents an error that occurs when comments are used within template expressions. | Error |
| LWC1199 | Represents an error that occurs when a template literal is used with the @wire configuration object. |
Error |
| LWC1200 | Represents an error that occurs when an invalid expression is used in the @wire configuration object. |
Error |
| LWC1201 | Represents a warning that occurs when an element with a slot attribute isn't a direct child of a component. |
Warning |
| LWC1703 | Represents an invalid module identifier. | Error |
| LWC1704 | Represents a missing resource value. | Error |
| LWC1709 | Represents a syntax error when parsing a file. | Error |