Error AtlasError Documentation and ResolutionReact documented errors
Browse documented React errors across hydration, hooks, rendering, and runtime behavior in modern React applications.
Configuration
Configuration errors
Rendering
Rendering errors
React error #448React createPortal was called on the serverReact detected createPortal being called during server rendering, which is unsupported because portals require a client-side DOM target.
React error #449React flushSync was called on the serverReact detected flushSync running during server render or module evaluation, even though synchronous DOM flushing is intended for client-side event or effect timing.
React error #418React hydration failed because server and client output differedReact detected a server-rendered tree that did not match the client render, so hydration failed and the subtree had to be regenerated on the client.
React error #422React recovered hydration by client rendering from the nearest Suspense boundaryReact hit a hydration problem but recovered by falling back to client rendering from the nearest Suspense boundary instead of abandoning the entire root.
React error #423React recovered hydration by client rendering the entire rootReact hit a hydration failure serious enough that it abandoned hydration for the whole root and switched to full client rendering.
React error #425React text content does not match server-rendered HTMLReact detected that text rendered on the client does not match the HTML produced by the server, causing hydration to fail for that subtree.
Runtime
Runtime errors
React error #482A Client Component was marked asyncReact detected an async Client Component, which is unsupported. This commonly happens when a server-oriented module is moved behind a 'use client' boundary accidentally.
React warningA component is changing an uncontrolled input to be controlledReact detected an input switching between controlled and uncontrolled states, which can lead to inconsistent UI behavior.
React error #109A valid React element or null must be returnedReact requires a component render method to return a valid React element or null, not undefined, an array, or another invalid value.
React error #185Can't perform a React state update on an unmounted componentReact detected a state update attempt after a component has been unmounted, indicating a memory leak or async issue.
React error #130Element type is invalidReact received an invalid component type, usually because a component import, export, or reference is wrong.
React error #309Function components cannot have string refsReact threw this error because a string ref was attached to a function component. String refs are legacy behavior and are not supported on modern function-component patterns.
React error #506Functions are not valid as a child of Client ComponentsReact received a function where rendered output was expected inside a Client Component, often because a component reference or callback was returned instead of JSX.
React error #201Invalid component elementReact was asked to mount into a target that is not a valid DOM element.
React error #418Invalid hook callReact detected a hook being used outside of a valid function component or custom hook context.
React error #152Nothing was returned from renderA component render path returned nothing instead of JSX or null.
React error #152Nothing was returned from renderA component failed to return any JSX, causing React to throw an error.
React error #31Objects are not valid as a React childReact attempted to render a JavaScript object directly instead of a renderable value.
React error #31Objects are not valid as a React childReact attempted to render a JavaScript object directly instead of a renderable value like a string, number, or element.
React error #119Only a React owner can have refsReact hit a ref ownership problem, usually because a ref is being attached in an unsupported way or multiple copies of React are loaded.
React error #498Only plain objects can be passed to Client Components from Server ComponentsReact threw this error because a Server Component attempted to pass a non-serializable value into a Client Component. This often happens with class instances, custom prototypes, or complex objects that cannot cross the server/client boundary safely.
React error #426React component suspended while responding to synchronous inputReact detected a suspension during synchronous user input, which can cause the current UI to be replaced by a fallback unless the update is scheduled as a transition.
React error #187React flushSync called inside a lifecycle methodReact reported that flushSync was called during render or lifecycle work, where React is already in the middle of rendering and cannot synchronously flush again.
React error #307React Hooks called outside a function componentReact detected Hook usage outside the body of a function component, which usually means a Hook was called from unsupported code or the Rules of Hooks were broken.
React error #404React invalid hook callReact detected a Hook being called in an unsupported location, such as outside a function component or custom Hook, and stopped rendering with the invalid hook call error.
React error #321React invalid hook call with mismatched versions or duplicate ReactReact reported an invalid hook call and included the common root causes: mismatched React and renderer versions, broken Rules of Hooks, or more than one React copy in the app.
React error #185React maximum update depth exceededReact detected an infinite or deeply recursive update loop and stopped rendering to prevent the component from updating forever.
React error #520React recovered from a concurrent rendering error by switching to sync renderReact encountered a concurrent rendering problem and fell back to synchronously rendering the full root to recover.
React error #300React rendered fewer hooks than expectedReact detected that a component called fewer Hooks than it did in a previous render, usually because execution returned early before all Hooks ran.
React error #310React rendered more hooks than during the previous renderReact found that a component called more Hooks than it did previously, which indicates the Hook order changed between renders.
React error #441React Server Components render failed in productionReact hit an error during a Server Components render. In production builds the detailed message is hidden and only a digest is exposed.
React error #311React should have a queue hook ordering errorReact hit an internal Hook state mismatch and reported that the component is likely calling Hooks conditionally, which breaks Hook bookkeeping.
React error #460React Suspense Exception from use caught incorrectlyReact surfaced a Suspense Exception because use was captured incorrectly, usually inside try/catch, instead of being rethrown or allowed to suspend normally.
React error #542React Suspense Exception from useActionState caught incorrectlyReact raised a Suspense Exception from useActionState because the interruption was captured incorrectly instead of being rethrown or allowed to suspend as designed.
React error #299React target container is not a DOM elementReact could not mount because the element passed to createRoot or legacy render APIs was missing, null, or not a valid DOM element.
React error #301React too many re-renders infinite loopReact detected a render loop where state updates keep causing immediate re-renders, and it stopped the component to prevent the app from locking up.
React error #390React tried to flush a boundary that was already aborted or flushedReact hit an internal boundary-state error during streaming or Suspense rendering, usually surfaced as a framework or runtime integration issue rather than a typical app-level mistake.
React error #188React unable to find node on an unmounted componentReact tried to access a DOM node associated with a component that has already been unmounted, which usually points to stale refs or imperative logic firing too late.
React error #143React.Children.only expected a single childReact received multiple children or a non-element value where an API explicitly expects exactly one React element child.
React error #461Selective hydration internal React error leaked to userspaceReact marks this as an internal error that should not normally surface to application users. If you see it, the problem is often a framework integration issue, a miscompiled React bundle, or a bug worth reducing and reporting.
React error #137Void element tag must not have children or dangerouslySetInnerHTMLReact threw this error because a void HTML element such as `img`, `input`, or `br` was rendered with children or `dangerouslySetInnerHTML`, which HTML does not allow for those tag types.