Unlock troubleshooting: rejected passwords, flattened output, and files that won't load

Solutions for the most common problems when removing a PDF password with Unlock. Everything Unlock does happens locally in your browser — so every fix below is also something you can retry as many times as you like without anything being uploaded.

"That password didn't open the PDF. Try again."

Cause: the password you entered doesn't decrypt this file. The PDF engine reports a missing and a wrong password the same way, so this message simply means "this isn't the right password yet." No file downloads until the password works; the field stays on screen so you can retry.

Fix:

1. Retype the password carefully — check Caps Lock, and watch for similar characters (O vs 0, l vs 1).
2. If you're pasting from a password manager or an email, make sure no leading or trailing space came along.
3. Some PDFs have two passwords: an open password (needed to open the file) and a permissions/owner password (restricts printing or copying). Enter the one you actually use to open the file; if you were given both, try each.
4. Confirm the password against the same file elsewhere — if it doesn't open the PDF in your usual viewer either, you have the wrong password or the wrong file version.
5. If you don't know the password at all, AttachKit can't help — it removes passwords you know, it doesn't crack or bypass them. Ask whoever sent the document.

"This PDF isn't password-protected — there's nothing to unlock"

Cause: the file parsed cleanly with no encryption. Common reasons: you already unlocked this copy (check your Downloads folder for a -unlocked.pdf duplicate), or the restriction you're running into isn't a password at all — for example a flattened form that can't be typed into.

Fix:

1. Use the file directly — it works as-is in Fill, Sign, or Redact.
2. If a form won't let you type into it, the form may have no interactive fields; Fill can still place text on top of the page.
3. If another viewer still asks for a password, you probably dropped a different copy of the file — compare file names and sizes.

"This file isn't a valid PDF (truncated, corrupted, or wrong file type)"

Cause: the bytes aren't a readable PDF. Typical culprits: an interrupted download, another file type renamed to .pdf (for example a Word document), or genuine corruption.

Fix:

1. Re-download the file from its source and let the download finish completely.
2. Try opening it in another PDF viewer — if that fails too, the file itself is broken, not the tool.
3. Re-export from the original application (or use its Print → Save as PDF option) and drop the fresh copy.

The unlocked copy has no selectable text

Cause: for most files Unlock decrypts in place and keeps text intact, but when that lossless re-save isn't possible it falls back to rendering each page as a 2x-resolution image. When this happens the download message says: "flattened to images. Run Searchable (OCR) to restore selectable text."

Fix:

1. Open Searchable (OCR) and drop the -unlocked.pdf copy.
2. Run OCR — it executes on your device and adds an invisible, selectable text layer over the page images.
3. The flattened pages are rendered at double resolution, so viewing and printing quality is preserved either way.

"That PDF is … MB. AttachKit caps drops at 100 MB"

Cause: the drop zone rejects files over 100 MB so a huge file can't freeze the browser tab while it's being read and parsed locally.

Fix:

1. For an unencrypted large file, split it first with Pages and process the parts.
2. For an encrypted file over 100 MB that's harder — Pages can't open a password-protected PDF either. Remove the password in a desktop app instead (macOS Preview or Adobe Acrobat: open with the password, then export/save a copy without one), and use AttachKit's tools on the result.
3. If the file is large because of scanned images, the desktop-unlocked copy can be shrunk afterwards with Compress.

Still stuck?

If none of this fixes it, contact support. Include the rough file size, where the PDF came from, and the exact message you saw — but never send the password. Because the file stays on your device, support can't see it; a screenshot of the error is the most useful thing you can share.