[Error] unhandlederror-AbstractContextKeyService has been disposed

[vs-code-engineering]

Error Message

unhandlederror-AbstractContextKeyService has been disposed

Stack Trace

    at Gki.contextMatchesRules (./src/vs/platform/contextkey/browser/contextKeyService.ts:322:0)
    at g5.createActionGroups (./src/vs/platform/actions/common/menuService.ts:285:0)
    at sxe.getActions (./src/vs/platform/actions/common/menuService.ts:453:0)
    at jn._updateToolbar (./src/vs/platform/actions/browser/toolbar.ts:392:0)
    at oIe.value (./src/vs/platform/actions/browser/toolbar.ts:378:0)
    at sIe._deliver (./src/vs/base/common/event.ts:1354:12)
    at sIe.fire (./src/vs/base/common/event.ts:1385:8)
    at sIe.resume (./src/vs/base/common/event.ts:1534:11)
    at (anonymous) (./src/vs/base/common/event.ts:1573:9)

Raw Stack Trace (minified)

Error: AbstractContextKeyService has been disposed     at Gki.contextMatchesRules (out/vs/workbench/workbench.desktop.main.js:1861:35731)     at g5.createActionGroups (out/vs/workbench/workbench.desktop.main.js:852:134241)     at sxe.getActions (out/vs/workbench/workbench.desktop.main.js:852:136731)     at jn._updateToolbar (out/vs/workbench/workbench.desktop.main.js:852:141545)     at oIe.value (out/vs/workbench/workbench.desktop.main.js:852:141274)     at sIe._deliver (out/vs/workbench/workbench.desktop.main.js:405:3066)     at sIe.fire (out/vs/workbench/workbench.desktop.main.js:405:3385)     at sIe.resume (out/vs/workbench/workbench.desktop.main.js:405:4674)     at out/vs/workbench/workbench.desktop.main.js:405:5031

Details

Property	Value
Bucket ID	d819bd63-3c52-10d4-5532-1260564a39e5
Version	1.116.0
Commit	560a9dba
Last Seen	Wed Apr 15 2026 23:58:30 GMT+0000 (Coordinated Universal Time)
Platforms	Linux, Mac, Windows
Product	VSCode

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This issue was automatically created from the VS Code Errors Dashboard

[vs-code-engineering]

Stable Release Anomaly Details

• Anomaly type: new
• Previous stable release: 1.115.0
• Current stable release: 1.116.0
• Users: 3,470
• Hits: 4,802
• Commit range: 41dd792b...560a9dba

⚠️ Insider build data was unavailable for commit range narrowing — the range above spans the full stable-to-stable delta.

Deminified Stack Summary

The error occurs when AbstractContextKeyService is used after disposal. The call path is:

1. contextKeyService.ts → contextMatchesRules — evaluates context key rules on a disposed service
2. menuService.ts → createActionGroups / getActions — menu service resolves action groups
3. toolbar.ts → _updateToolbar — toolbar refresh triggers the evaluation

This indicates a disposed context key service is still being referenced during toolbar updates, likely due to a lifecycle mismatch where a toolbar component outlives its owning context key service scope.

Related Issues

• AbstractContextKeyService has been disposed #246652 — Same error (AbstractContextKeyService has been disposed) through contextMatchesRules → menuService, but triggered via gutterFeature.ts (diff editor) instead of toolbar.ts. Assigned to @hediet on "On Deck" milestone.
• AbstractContextKeyService has been disposed #260086, AbstractContextKeyService has been disposed #210947 — Older instances of the same error pattern.
• [Error] unhandlederror-AbstractContextKeyService has been disposed #310756 — Same error message but different call path (createOverlay → aiCustomizationListWidget), Agents product.

Generated by errors-stable-scan · ● 8.7M · ◷

[vs-code-engineering]

🔍 Error Investigation

Summary

The error AbstractContextKeyService has been disposed is thrown when a MenuWorkbenchToolBar's debounced onDidChange event fires after the scoped IContextKeyService it references has been disposed. This is a race condition between the DebounceEmitter's setTimeout-based delivery and view lifecycle disposal. The Agents/Sessions feature added in 1.116.0 (particularly ChangesViewPane) creates many rapidly-changing scoped context keys, significantly increasing the probability of this race.

Culprit Commit

No single culprit commit was identified. The error is a pre-existing race condition in the DebounceEmitter → toolbar update path that became triggerable at scale due to the many new Agents/Sessions features added across multiple PRs in 1.116.0. The ChangesViewPane introduced by @lszomoru creates 10+ scoped context keys that update via bufferChangeEvents() on every session state change, widening the timing window for the race.

The commit range spans full stable-to-stable (1.115.0→1.116.0). Insider data shows the error first appeared in build 1dfb3b9d (Apr 13). The regression window (~Apr 12–13) contains ~30 commits, none of which individually modify toolbar.ts or menuService.ts.

Code Flow

sequenceDiagram
    participant CKS as ScopedContextKeyService
    participant Menu as Menu (DebounceEmitter)
    participant Toolbar as MenuWorkbenchToolBar
    participant MenuInfo as MenuInfo

    CKS->>Menu: onDidChangeContext (context key changes)
    Note over Menu: DebounceEmitter.fire():<br/>pauses, queues event,<br/>starts setTimeout(delay)
    Note over CKS: ⚠️ View disposed →<br/>ScopedContextKeyService<br/>._isDisposed = true
    Menu->>Menu: setTimeout fires → resume()
    Menu->>Toolbar: onDidChange callback
    Toolbar->>MenuInfo: _updateToolbar() → getActions()
    MenuInfo->>CKS: createActionGroups() → contextMatchesRules()
    Note over CKS: 💥 _isDisposed === true<br/>throws "AbstractContextKeyService<br/>has been disposed"

Loading

Affected Files

File	Role
src/vs/platform/contextkey/browser/contextKeyService.ts:322	Crash site — contextMatchesRules() throws when _isDisposed is true
src/vs/platform/actions/common/menuService.ts:285	Data flow — createActionGroups() calls contextMatchesRules() on potentially disposed CKS
src/vs/platform/actions/browser/toolbar.ts:392	Trigger — _updateToolbar() invoked by debounced onDidChange callback
src/vs/base/common/event.ts:1569-1578	Root cause — DebounceEmitter doesn't clear _handle timeout on disposal
src/vs/sessions/contrib/changes/browser/changesView.ts:675	Trigger source — bufferChangeEvents() batch-updates 10+ context keys on the scoped CKS

Repro Steps

1. Open VS Code with the Agents/Sessions feature active (1.116.0+)
2. Start or open an agent session so the Changes view (ChangesViewPane) is visible
3. Perform an action that causes rapid session state changes (e.g., switching sessions, committing, or closing a session)
4. While context keys are being updated, close the view or dispose the session quickly
5. The debounced onDidChange timer fires after the scoped CKS is disposed → error

This is a timing-sensitive race condition. It's more likely when many context keys change in rapid succession (which bufferChangeEvents() at line 675 ensures) and the view is closed within the debounce delay window (~100ms default).

Fix Proposal

Three possible approaches, in order of preference:

1. Fix in DebounceEmitter.dispose() (best — prevents the root cause):

   • Fix location: src/vs/base/common/event.ts → DebounceEmitter class
   • Approach: Override dispose() to call clearTimeout(this._handle) before calling super.dispose(). This ensures no debounced events fire after disposal. This is the most defensive fix since it prevents the entire class of debounce-after-dispose errors.

2. Guard in MenuInfo.createActionGroups() (defense in depth):

   • Fix location: src/vs/platform/actions/common/menuService.ts → createActionGroups()
   • Approach: Before calling this._contextKeyService.contextMatchesRules() at line 285, check if the CKS is disposed. If disposed, skip the item (or return empty results). This mirrors the pattern already used in getContextKeyValue() at contextKeyService.ts:333 which returns undefined when disposed instead of throwing.

3. Guard in contextMatchesRules() (most conservative):

   • Fix location: src/vs/platform/contextkey/browser/contextKeyService.ts → contextMatchesRules()
   • Approach: Change line 321-322 from throwing to returning false when disposed, matching the graceful degradation pattern in getContextKeyValue(). This would prevent all callers from hitting this error.

Recommended Owner

@jrieken — platform actions owner (toolbar.ts, menuService.ts, event.ts). The fix belongs in the platform event/menu infrastructure. Related issue #246652 follows the same error pattern through contextMatchesRules → menuService.

Generated by errors-investigate · ● 34.4M · ◷

[vs-code-engineering]

Related Error Buckets

This error bucket continues to appear in v1.117.0-insider (previously tracked since v1.116.0):

Bucket ID	Error Message	Users	Version
0819ee27	AbstractContextKeyService has been disposed	310	1.117.0-insider

Stack path: contextKeyService.ts:322 → menuService.ts:285 → toolbar.ts:392 — same disposed-context-key-service-during-toolbar-update pattern as bucket d819bd63 in 1.116.0. Bucket ID drift across builds.

Generated by errors-regression-scan · ● 7M · ◷

[vs-code-engineering]

Related Error Buckets

This error bucket continues to appear in v1.118.0-insider (previously tracked since v1.116.0):

Bucket ID	Error Message	Users	Version
56b67fd1	AbstractContextKeyService has been disposed	21	1.118.0-insider

Stack path: contextKeyService.ts:322 → menuService.ts:285 → toolbar.ts:392 — same disposed-context-key-service-during-toolbar-update pattern as bucket d819bd63 in 1.116.0 and bucket 0819ee27 in 1.117.0-insider. Bucket ID drift across builds.

Generated by errors-regression-scan

Generated by errors-regression-scan · ● 10.1M · ◷

[vs-code-engineering]

Stable Release Anomaly — Continuing in 1.117.0

This error continues in stable 1.117.0 with a new bucket ID and a different call path:

Bucket ID	Error Message	Users	Version
321426cc	AbstractContextKeyService has been disposed	1,122	1.117.0

Stack path: contextKeyService.ts → chatTipService.ts → chatServiceImpl.ts → chatWidget.ts — a different trigger path from the primary bucket (d819bd63, which goes through toolbar.ts). This variant fires through the chat tip service evaluating context keys on a disposed scoped context key service, rather than through toolbar updates.

The same root cause applies — AbstractContextKeyService.contextMatchesRules() is called after the scoped service is disposed, but the trigger is chat widget tip evaluation rather than toolbar refresh.

Generated by errors-stable-scan · ● 10.2M · ◷