Fix a Failed Profile Preflight Check

Before every browser profile launch, MaskPilot checks the current sign-in, profile configuration, browser version, fingerprint, extensions, proxy, and local data. When “Preflight check failed” appears, that launch has stopped. Fix the items marked “Failed,” then select “Check again and launch.”

The check confirms lightweight launch prerequisites only. It does not download a browser, replace local profile data, or run an online proxy test. Passing every item means the profile can enter the later launch stages; it does not guarantee that a download, live exit check, or browser process will succeed.

Distinguish the three statuses

Status	Meaning	Blocks launch?
Passed	The current check found no problem	No
Warning	Launch can continue, but a default or incomplete value needs attention	Not by itself
Failed	A launch prerequisite is not satisfied	Yes

If warnings and failures appear together, address the failed items first. A missing profile name or incomplete fingerprint can produce a warning. The missing fingerprint values use the defaults described on the page; you still need to confirm the profile name yourself.

Fix each check in order

Sign-in or profile

• Sign in to MaskPilot again, then launch from the current profile list instead of continuing from a stale page.
• Refresh the list and confirm that the profile still exists and that the primary account or team member still has access.
• If only one profile cannot be read, record its name and the visible message. Do not create a replacement with the same name in an attempt to overwrite the original data.

Browser

“No browser version is available” or “The assigned browser version is unavailable” means that the profile has no usable version for this device. Select “Go to browser downloads,” confirm that the target version is listed, and finish the download before returning to the profile list.

Even after preflight passes, the actual launch verifies the local browser files and downloads them when needed. If a later stage stops during preparation, download, verification, or installation, use the browser download troubleshooting steps instead. Do not copy an untrusted browser package into the client directories.

Fingerprint

An incomplete fingerprint normally appears as a warning and does not block launch by itself. Open the profile editor and review the operating system, browser version, and core fingerprint settings. Save the profile, fully close it, and launch again. Do not repeatedly randomize a stable configuration merely to remove a warning.

Extensions

When the extension check fails, select “Manage extensions” and verify:

1. Each selected store extension is still enabled and supports the current browser version.
2. Local extension files still exist on this device and their directories are readable.
3. A local extension does not require a browser version newer than the profile uses.
4. The all-profiles, tag, or manual scope still includes the intended profile.

Fix the extension identified by the page before retrying. For a store extension, continue with extension compatibility after a browser update. For unavailable local files, use the local extension import checklist to verify the directory and manifest.

Proxy

The preflight check only verifies that the saved standard or multi-hop configuration can be parsed by the client. It does not test the node online or measure its latency at this stage. If “Proxy configuration is invalid” appears, select “Check proxy,” then verify the protocol, host, port, authentication, and complete upstream route. Re-import an advanced configuration from the provider when its connection fields need to change.

If configuration passes but the later launch still cannot obtain an exit IP or time zone, run “Check connection” and “Check full connection,” then follow the proxy launch troubleshooting steps. The device network, VPN, firewall, or node can change between two checks.

Local data or browser state

No local directory is expected before a first launch; the later launch flow creates it. When local data already exists, its directory must be readable and cannot still be held by another browser process for the same profile.

1. Check the taskbar and other desktops, then close the profile’s existing browser window normally.
2. Wait for shutdown to finish before selecting “Check again and launch.”
3. Do not manually delete the profile directory, lock files, or local backups, and do not repeatedly force-quit the client.
4. If the page reports an inaccessible directory, an invalid path, or an unknown process state, preserve the original device and data and use the page action to contact support.

If the profile still appears to be in use locally, see the difference between a local process and a run record.

Why can launch still fail after preflight passes?

The result describes the prerequisites at the moment of the check. The real launch may still download or verify the browser, retrieve current configuration, restore profile data, inspect the live proxy exit, and create a browser process. A change in the network, disk space, security software, proxy node, or profile data can fail one of those later stages.

Change one variable for one identified stage, then check again. Microsoft’s browser-profile startup guidance similarly works through active processes, data-directory access, and sync in sequence. In MaskPilot, follow the specific item shown in preflight and the product boundaries documented here.

Before contacting support

Record the profile name, client and browser versions, every failed item, the complete message, approximate time, and steps already attempted. Redact website accounts, proxy usernames and passwords, cookies, session data, and other secrets from screenshots. Do not send a local profile directory or an unredacted configuration file.