[Regression] Cannot read properties of undefined (reading 'resize') — terminalInstance._resize

[vs-code-engineering]

Error Message

unhandlederror-Cannot read properties of undefined (reading 'resize')

Stack Trace

    at Fv._resize (./src/vs/workbench/contrib/terminal/browser/terminalInstance.ts:2073:0)
    at Fv.setVisible (./src/vs/workbench/contrib/terminal/browser/terminalInstance.ts:1433:0)
    at nwe.value (./src/vs/workbench/contrib/terminal/browser/terminalInstance.ts:591:0)
    at T._deliver (./src/vs/base/common/event.ts:1364:12)
    at T._deliverQueue (./src/vs/base/common/event.ts:1375:8)
    at T.fire (./src/vs/base/common/event.ts:1399:8)
    at rZt.triggerConfigurationChange (./src/vs/workbench/services/configuration/browser/configurationService.ts:1124:0)
    at rZt.onDefaultConfigurationChanged (./src/vs/workbench/services/configuration/browser/configurationService.ts:773:0)
    at nwe.value (./src/vs/workbench/services/configuration/browser/configurationService.ts:156:0)
    at T._deliver (./src/vs/base/common/event.ts:1364:12)
    at T._deliverQueue (./src/vs/base/common/event.ts:1375:8)
    at T.fire (./src/vs/base/common/event.ts:1399:8)
    at a.onDidUpdateConfiguration (./src/vs/platform/configuration/common/configurations.ts:49:33)
    at a.onDidUpdateConfiguration (./src/vs/workbench/services/configuration/browser/configuration.ts:92:8)
    at nwe.value (./src/vs/platform/configuration/common/configurations.ts:38:148)
    at T._deliver (./src/vs/base/common/event.ts:1364:12)
    at T._deliverQueue (./src/vs/base/common/event.ts:1375:8)
    at T.fire (./src/vs/base/common/event.ts:1399:8)
    at sri.updateConfigurations (./src/vs/platform/configuration/common/configurationRegistry.ts:410:0)
    at byi (./src/vs/workbench/contrib/terminalContrib/suggest/common/terminalSuggestConfiguration.ts:259:0)

Raw Stack Trace (minified)

TypeError: Cannot read properties of undefined (reading 'resize')     at Fv._resize (out/vs/workbench/workbench.desktop.main.js:4032:3214)     at Fv.setVisible (out/vs/workbench/workbench.desktop.main.js:4031:7204)     at nwe.value (out/vs/workbench/workbench.desktop.main.js:4028:25273)     at T._deliver (out/vs/workbench/workbench.desktop.main.js:405:3269)     at T._deliverQueue (out/vs/workbench/workbench.desktop.main.js:405:3358)     at T.fire (out/vs/workbench/workbench.desktop.main.js:405:3693)     at rZt.triggerConfigurationChange (out/vs/workbench/workbench.desktop.main.js:4957:61813)     at rZt.onDefaultConfigurationChanged (out/vs/workbench/workbench.desktop.main.js:4957:52606)     at nwe.value (out/vs/workbench/workbench.desktop.main.js:4957:39341)     at T._deliver (out/vs/workbench/workbench.desktop.main.js:405:3269)     at T._deliverQueue (out/vs/workbench/workbench.desktop.main.js:405:3358)     at T.fire (out/vs/workbench/workbench.desktop.main.js:405:3693)     at a.onDidUpdateConfiguration (out/vs/workbench/workbench.desktop.main.js:4956:2736)     at a.onDidUpdateConfiguration (out/vs/workbench/workbench.desktop.main.js:4957:14378)     at nwe.value (out/vs/workbench/workbench.desktop.main.js:4956:2450)     at T._deliver (out/vs/workbench/workbench.desktop.main.js:405:3269)     at T._deliverQueue (out/vs/workbench/workbench.desktop.main.js:405:3358)     at T.fire (out/vs/workbench/workbench.desktop.main.js:405:3693)     at sri.updateConfigurations (out/vs/workbench/workbench.desktop.main.js:434:74224)     at byi (out/vs/workbench/workbench.desktop.main.js:1030:1465)     at kIe._updateConfiguration (out/vs/workbench/workbench.desktop.main.js:4137:15478)     at nwe.value (out/vs/workbench/workbench.desktop.main.js:4137:14964)     at T._deliver (out/vs/workbench/workbench.desktop.main.js:405:3269)     at T.fire (out/vs/workbench/workbench.desktop.main.js:405:3588)     at uii._fn (out/vs/workbench/workbench.desktop.main.js:1045:34691)     at uii.dispose (out/vs/workbench/workbench.desktop.main.js:403:1320)     at je (out/vs/workbench/workbench.desktop.main.js:403:747)     at vy.clear (out/vs/workbench/workbench.desktop.main.js:403:1636)     at vy.dispose (out/vs/workbench/workbench.desktop.main.js:403:1546)     at nwe.value (out/vs/workbench/workbench.desktop.main.js:4028:26855)     at T._deliver (out/vs/workbench/workbench.desktop.main.js:405:3269)     at T._deliverQueue (out/vs/workbench/workbench.desktop.main.js:405:3358)     at T.fire (out/vs/workbench/workbench.desktop.main.js:405:3693)     at Fv.dispose (out/vs/workbench/workbench.desktop.main.js:4031:5595)     at out/vs/workbench/workbench.desktop.main.js:4033:42245     at new Promise (<anonymous>)     at XC.safeDisposeTerminal (out/vs/workbench/workbench.desktop.main.js:4033:42201)     at out/vs/workbench/workbench.desktop.main.js:4021:10835     at Spt._runForSelectionOrInstance (out/vs/workbench/workbench.desktop.main.js:4021:11101)     at it._actionCallback (out/vs/workbench/workbench.desktop.main.js:4021:10781)     at it.run (out/vs/workbench/workbench.desktop.main.js:411:30713)     at cIe.runAction (out/vs/workbench/workbench.desktop.main.js:411:31137)     at cIe.runAction (out/vs/workbench/workbench.desktop.main.js:4007:26911)     at cIe.run (out/vs/workbench/workbench.desktop.main.js:411:31040)     at ts.onClick (out/vs/workbench/workbench.desktop.main.js:851:17488)     at HTMLLIElement.<anonymous> (out/vs/workbench/workbench.desktop.main.js:851:17175)

Details

Property	Value
Bucket ID	cab7157f-af52-52f4-667e-28136605407c
Version	1.122.0-insider
Commit	7d7e9513
Last Seen	Wed May 20 2026 23:55:17 GMT+0000 (Coordinated Universal Time)
Platforms	Mac, Windows, Linux
Product	VSCode

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This issue was automatically created from the VS Code Errors Dashboard

[vs-code-engineering]

Regression Details

• Product: VSCode
• Regression type: new
• Affected users: 195 (across 4 coalesced buckets)
• Platforms: Windows, Mac, Linux
• Last release without this error: 1.121.0-insider (May 18 16:12)
• First release with this error: 1.121.0-insider (May 18 23:45)
• Commit range: 553c7275...e9f40e53

Coalesced Buckets

All 4 buckets share the same root cause — this._xterm is undefined when _resize is called during terminal dispose/layout:

Bucket	Users	Trigger
cab7157f	73	setVisible → config change during dispose
c66fbeaa	61	layout → webgl renderer dispose
2b655583	37	layout → instance removal
cc80d001	24	layout → webgl renderer dispose during shutdown

Deminified Stack (representative)

terminalInstance.ts:2073 — _resize
terminalInstance.ts:1433 — setVisible
terminalInstance.ts:591  — (event handler)
event.ts:1364            — _deliver
event.ts:1375            — _deliverQueue
event.ts:1399            — fire

Generated by errors-regression-scan · ● 4.6M · ◷