A Proton Drive sign-in involves several independent parts: the page or app you opened, the account password you typed, an optional second factor, the local state of your decrypted library on that device, and the sync connection that reconciles your folders with your other devices. The phrase "I cannot get into Proton Drive" points at none of these specifically, and guessing wastes the small number of attempts you have before rate limiting kicks in.
Before changing anything, write down four facts: the exact message on screen, the local time it appeared, the device and app you were using, and whether the failure happens in the desktop app, the mobile app, the browser version, or more than one of them. Never write down the account password itself, and never send a screenshot containing a partially filled password field to anyone.
Confirm that you opened the real entry point
Most alarming "sign-in problems" are not password problems at all. A look-alike page, a mistyped hostname, or an expired certificate will reject a perfectly correct password, and inside a small window the error can look identical to a wrong password.
Check the address bar before you check anything else. A genuine Proton domain uses a valid certificate, loads without a browser warning, and never asks for your account password immediately after a redirect from an email link. If you arrived through a link in a message, open the service from your own bookmark instead. If the browser shows a certificate warning, close the tab rather than clicking through it. Our overview of what a real Proton Drive login looks like is a useful second reference once the address looks correct.
Rule out the keyboard before everything else
Account passwords are long, so a single mistyped capital or a wrong keyboard layout rejects them reliably. Check that caps lock is off, that the input language matches the layout you memorised the password in, and that the field simply accepts spaces. A trailing space, added by autocorrect or an accidental keypress, is one of the most common causes of a rejected password on an account that worked yesterday.
Use the reveal option built into the field if the client offers one, or paste the password from a trusted password manager rather than typing it from memory. Revealing characters in front of someone else is a different decision from typing them, and on a shared screen a revealed password is a visible one.
Understand what "accepted but locked" actually means
There is a meaningful difference between a rejected password and an accepted one that leaves your library sealed. Acceptance means the password you entered produced the correct encryption keys. What happens next belongs to a later stage, and those later stages have entirely different causes.
A pending two-factor prompt, a device that is offline and therefore cannot complete a sync check, a security hold triggered by repeated failed attempts on the account, or an expired session on the device you are trying to add can all produce successful password entry followed by a refusal. Waiting fifteen minutes without further attempts resolves rate limiting far more often than any setting change.
Because the password is never stored in readable form anywhere, changing it is not a diagnostic step. If you can remember it and it is being rejected, the problem is not that you forgot it.
Separate a local problem from an account problem
A library that will not open on one device but appears normally on your phone is a device problem, and the account is fine. A library that fails everywhere at once points to the account, the network, or an account-side security measure.
Test general connectivity by loading an unrelated site. On filtered, captive, or restricted guest Wi-Fi a sync step may never complete even though your password is correct. Many clients can open an already-synced library in a read-only offline mode, which lets you confirm that your stored files are intact rather than assuming they are gone.
Do not clear local application data as a first response. On some platforms that discards cached credentials you would then have to re-enter file by file, and it destroys the state a support conversation would need.
Check active sessions and devices you no longer own
Every signed-in device holds an encrypted copy of your library. A phone you sold, a laptop you returned to an employer, or a browser profile on a shared machine can keep working long after you stopped thinking about it. If a sign-in you are attempting is being refused on a device you no longer recognise, reviewing and removing those sessions is often the actual fix.
Sign out of devices you have finished with rather than relying on a timeout. A session that never ends is a standing copy of your file index on hardware you are not tracking.
Work through the two-factor path deliberately
Multi-factor authentication is a separate step with separate failure modes. If a prompt appears, approve it only when it follows a sign-in you just started and mentions the account you expect. If no prompt arrives, the registered method may be an authenticator app whose codes have drifted, a phone number that no longer receives messages, or a hardware key that is no longer paired.
Never let another person read a code out to you, and never approve an unsolicited request. An unexpected approval prompt is either a stale request or an attempt to sign in as you, and approving it is worse than ignoring it.
Build a support report that is safe to send
A useful report contains the product and app version, the platform and its version, the exact error wording, the timestamp with a time zone, which of your devices are affected, whether the library opens in offline mode, and the last action you completed successfully. That last detail is often the most informative line in the whole message.
Remove everything sensitive before sending. Redact usernames, email addresses, folder names you consider private, partial passwords, recovery codes, and any on-screen notification that might contain an account identifier. A screenshot cropped tightly around the error text communicates more than a full window capture.
Remember what this website can and cannot do. We are an independent fan site, so we cannot unlock your library, reset your password, or inspect your account. Only Proton's official support channel can act on your account, and the report you prepare here is designed to make that conversation short.
A short order of operations
When you are stuck, this order resolves the majority of cases. Confirm the domain and certificate. Confirm the keyboard and layout. Try once more and wait if a limit is likely. Check connectivity. Check whether the library opens offline. Check the second factor. Then write the report. Skipping to the last step without the earlier checks is what turns a five-minute fix into an afternoon.