vuejs/core · error · Error

${key} compat has been disabled.

Error message

${key} compat has been disabled.

What it means

Thrown by assertCompatEnabled in @vue/runtime-core's migration build when a Vue 2 feature (identified by a DeprecationTypes key) is used but compat is disabled for that feature or globally. assertCompatEnabled is reserved for features that are completely removed in the non-compat build — calling them without compat enabled is unrecoverable. compatConfig.ts:599 throws `${key} compat has been disabled.`

Source

Thrown at packages/runtime-core/src/compat/compatConfig.ts:599

    : rawMode

  if (mode === 2) {
    return val !== false
  } else {
    return val === true || val === 'suppress-warning'
  }
}

/**
 * Use this for features that are completely removed in non-compat build.
 */
export function assertCompatEnabled(
  key: DeprecationTypes,
  instance: ComponentInternalInstance | null,
  ...args: any[]
): void {
  if (!isCompatEnabled(key, instance)) {
    throw new Error(`${key} compat has been disabled.`)
  } else if (__DEV__) {
    warnDeprecation(key, instance, ...args)
  }
}

/**
 * Use this for features where legacy usage is still possible, but will likely
 * lead to runtime error if compat is disabled. (warn in all cases)
 */
export function softAssertCompatEnabled(
  key: DeprecationTypes,
  instance: ComponentInternalInstance | null,
  ...args: any[]
): boolean {
  if (__DEV__) {
    warnDeprecation(key, instance, ...args)
  }
  return isCompatEnabled(key, instance)

View on GitHub (pinned to a2b40db9a8)

Solutions

1. Re-enable the specific feature in configureCompat (set the DeprecationTypes key to true or 'suppress-warning') until you have removed its usages.
2. Migrate the offending code to the Vue 3 equivalent for the named DeprecationTypes key (the key in the message tells you which feature).
3. If using the migration build, ensure you are actually on `vue/compat` and MODE is 2, not 3.
4. Search the codebase for the Vue 2 pattern indicated by the key and replace each call site.

Example fix

// before
import { configureCompat } from 'vue'
configureCompat({ MODE: 3, RENDER_FUNCTION: false })
// ... code still uses the removed render-function compat path

// after
configureCompat({ MODE: 2, RENDER_FUNCTION: true })
// or migrate the call site to the v3 API, then drop the flag

// Before using a removed Vue 2 feature, check compat is enabled.
import { isCompatEnabled } from 'vue/compat'
import { DeprecationTypes } from 'vue/compat'
function guardedFilterUsage(key = DeprecationTypes.FILTERS) {
  if (!isCompatEnabled(key, null)) {
    throw new Error(`${key} requires compat enabled; migrate to a method/computed.`)
  }
  // ... legacy filter usage
}

function compatFeatureEnabled(key: number, instance: any): boolean {
  return isCompatEnabled(key, instance)
}

try {
  assertCompatEnabled(DeprecationTypes.FILTERS, instance)
  // ... legacy code path
} catch (e) {
  // migrate the call site, or re-enable the feature in configureCompat
  throw e
}

When it happens

Trigger: Using the `vue/compat` (migration) build with compat MODE set to 3 (or a specific feature flag set to false) while still calling a fully-removed Vue 2 API such as the `filters` option, `$listeners`, the `destroy`/`destroyed` lifecycle hooks (in removed form), or event EventBus patterns guarded by assertCompatEnabled.

Common situations: Migrating from Vue 2 to 3 and disabling a deprecation feature flag (`configureCompat({ FEATURE_X: false })`) while code still uses that feature; running on the standard v3 build (no compat) against code expecting Vue 2 semantics; selectively turning off compat before removing the last usage.

Related errors

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• [@vue/compiler-sfc] <script> and <script setup> must have th
• [@vue/compiler-sfc] SFC contains no <script> tags.
• [@vue/compiler-sfc] `modules` option is not supported in the
• [@vue/compiler-sfc] `modules` option can only be used with c

AI-assisted analysis of vuejs/core@a2b40db9a8 (2026-08-12). Data as JSON: /api/errors/8243642a5b5ce6ca. Report an issue: GitHub.