Cursor won't open or stuck in a login loop? Fixes that actually work (2026)

TL;DR: Most Cursor launch and login-loop problems come from a corrupted local config, a stale auth token, or a proxy/VPN blocking the sign-in callback. Clear Cursor's cache and stored auth, launch once as admin, and check your network. If it still loops, the sign-in service or your account session is the culprit — not your machine.

The symptoms

Won't open at all

You click Cursor and nothing happens, or the window flashes and disappears.

Blank / white screen

The window opens but never renders the editor.

Endless login loop

You sign in, it looks fine, then it drops you back to the sign-in page again.

Fix 1 — clear the corrupted local state

A bad cache or a half-written config is the most common reason Cursor won't open or shows a blank screen. Fully quit Cursor (check Task Manager for leftover Cursor processes), then clear its local app data and relaunch. Cursor rebuilds the config on next start.

Clear Cursor state (Windows)

1. Fully quit CursorEnd all Cursor.exe processes in Task Manager so nothing holds the config open.
2. Back up and clear app dataRename or clear %APPDATA%\Cursor and %LOCALAPPDATA%\Cursor (keep a backup copy first).
3. RelaunchStart Cursor again; it recreates a clean config. A blank-screen or won't-open issue usually clears here.

Fix 2 — break the login loop

A login loop usually means a stale or invalid auth token that keeps getting rejected. Sign out fully, remove the stored token, and sign in again. If you're behind a VPN or corporate proxy, the sign-in callback (the redirect back into the app) can get blocked — try once on a clean network to confirm.

Stop the login loop

1. Sign out and clear stored authSign out inside Cursor, then clear the cached login token in %APPDATA%\Cursor so it can't be reused.
2. Try a clean networkDisable VPN/proxy and sign in once. If it works, your network was blocking the OAuth callback.
3. Check the service statusIf it loops on every network and machine, the sign-in service or your account session is the issue — not local config.

If Cursor keeps signing you out across machines, it's a server-side session problem, not something you can fix locally. Log a support ticket rather than reinstalling repeatedly.

When it keeps happening

If you're doing this dance every week, it's worth stepping back. A lot of these failures come from the editor being tightly coupled to a hosted account and sign-in flow. A local, open agent you run yourself — bring your own model key, no forced login loop — sidesteps the whole category. You keep your editor; you just stop depending on someone else's auth service to get work done.

FAQ

Why does Cursor keep sending me back to the login page?

Almost always a stale auth token or a blocked sign-in callback. Clear the stored token in %APPDATA%\Cursor and sign in again; if you're on a VPN/proxy, try a clean network so the OAuth redirect isn't blocked.

Cursor opens to a blank white screen — what now?

That's usually a corrupted local cache. Fully quit Cursor, clear %APPDATA%\Cursor and %LOCALAPPDATA%\Cursor (back them up first), and relaunch so it rebuilds a clean config.

Does reinstalling Cursor fix the login loop?

Not reliably. A reinstall often keeps the old app data, so the bad token survives. Clear the stored auth first; a plain reinstall alone usually doesn't break the loop.

Cursor won't open or stuck in a login loop? Here's how to actually fix it