Using @playwright/mcp@0.0.79 with HTTP transport and --shared-browser-context:
- Clients A and B each call a browser tool.
- A calls
browser_close.
- A calls
browser_tabs { action: "new", url: "https://example.com" }.
A then fails until restart with:
TypeError: Cannot read properties of undefined
(reading 'checkUrlAndNavigate' / 'waitForInitialized')
browser_close disposes A's Context, but its cached backendPromise is cleared only on disconnected. Because B keeps the shared browser alive, no disconnect occurs and A reuses the disposed backend.
Expected: explicit close invalidates A's cached backend so the next call creates a fresh one.
This appears to be a 0.0.79 regression. Please clear backendPromise on explicit close and add a two-client regression test.
Version: @playwright/mcp 0.0.79, playwright-core 1.63.0-alpha-2026-08-05.
Using
@playwright/mcp@0.0.79with HTTP transport and--shared-browser-context:browser_close.browser_tabs { action: "new", url: "https://example.com" }.A then fails until restart with:
browser_closedisposes A'sContext, but its cachedbackendPromiseis cleared only ondisconnected. Because B keeps the shared browser alive, no disconnect occurs and A reuses the disposed backend.Expected: explicit close invalidates A's cached backend so the next call creates a fresh one.
This appears to be a 0.0.79 regression. Please clear
backendPromiseon explicit close and add a two-client regression test.Version:
@playwright/mcp 0.0.79,playwright-core 1.63.0-alpha-2026-08-05.