WebKit launchPersistentContext fails on Windows with 'Initial load failed'

[padamson]

Description

launchPersistentContext fails on WebKit with Playwright driver 1.56.1 on macOS ARM64 (and previously on Windows).

Error

Protocol error (Playwright.setDownloadBehavior): Browser started with no default context

The error originates in wkBrowser.js — WebKit's browser process starts but doesn't create a default browsing context, so when the server calls Playwright.setDownloadBehavior during WKBrowserContext._initialize, there's no context to configure.

Stack trace

at WKSession.send (wkConnection.js:104:12)
at WKBrowserContext._initialize (wkBrowser.js:194:49)
at WKBrowser.connect (wkBrowser.js:72:45)
at WebKit.connectToTransport (webkit.js:47:39)
at WebKit._innerLaunch (browserType.js:137:48)
at WebKit.launchPersistentContext (browserType.js:86:23)

Current workaround

Skipped the WebKit portion of test_launch_persistent_context_cross_browser integration test.

Resolution path

• Check if newer Playwright server versions fix this
• May be resolved by upgrading the bundled driver beyond 1.56.1

[padamson]

Update: Playwright 1.58.2

The macOS ARM64 issue is fixed — WebKit launchPersistentContext works correctly on macOS with Playwright 1.58.2 (commit 12d0a33).

However, Windows still fails with a different error:

Initial load failed
  at WKPage.handleProvisionalLoadFailed (wkPage.js:271:54)
  at WKBrowser._onProvisionalLoadFailed (wkBrowser.js:168:12)

This appears to be an upstream Playwright limitation with WebKit on Windows. The cross-browser persistent context test now skips WebKit on Windows.

Keeping this issue open to track the Windows case.

[padamson]

v0.12.0 Assessment Update (2026-04-19)

Re-tested with Playwright 1.58.2

• ✅ macOS: Works (original bug fixed in 1.58.2, landed in v0.8.7)
• ✅ Linux: Works
• ❌ Windows: Still fails, but with a distinct error:

Original (now fixed): Browser started with no default context at wkBrowser.js:194
Current (still reproducing): Initial load failed at wkPage.js:handleProvisionalLoadFailed

Research into upstream status

Checked Playwright releases through v1.59.1 (current latest) and language bindings:

• No fix in 1.59.x — the "Initial load failed" failure is tracked upstream as microsoft/playwright#36936 ("All webkit builds up from 2155 crash on win10 / server 16", still open)
• Microsoft's position (from issue #38014): "Windows 10 is not officially supported by Playwright... it is likely that WebKit will not properly start for you on Windows 10"
• Official resolution path: experimental channel: "webkit-wsl" — runs WebKit under WSL to bypass native Windows build issues
• No language binding (Python, Java, .NET) has a workaround for this on Windows — they're thin wrappers over the same driver

Root cause

From wkPage.ts ~line 290: persistent mode pushes about:blank as the starting URL to complete initialization; native Windows WebKit fails this initial load. Non-persistent (browser.new_context()) uses --no-startup-window instead, which is why it still works on Windows.

Action taken in v0.12.0

• Windows skip restored in test_launch_persistent_context_cross_browser with updated rationale
• README "Known limitation" note added, pointing to upstream issues and WSL workaround
• No driver upgrade needed (1.59.x doesn't fix it)
• channel is already exposed via LaunchOptions/BrowserContextOptions, so users can pass channel: "webkit-wsl" today if they have WSL

Tracking

Keeping this issue open to track upstream resolution. Primary upstream signal to watch:

• microsoft/playwright#37036 — webkit-wsl GA
• microsoft/playwright#36936 — Windows WebKit crashes

Next re-assessment: when webkit-wsl becomes stable or a Playwright release notes a Windows WebKit fix.