Header & footer troubleshooting: password-protected files, the disabled button, question marks, overlapping text

Header & footer runs entirely in your browser — no upload, no queue — so most runs finish in a moment. When something goes wrong, it's usually one of the cases below.

"This PDF is password-protected, so it can't be opened to stamp."

Cause: the file is encrypted. The tool has to open the PDF and draw onto every page, which an encrypted file doesn't allow without its password.

Fix:

1. Follow the Remove the password first → link shown in the error notice (it goes to the Unlock tool).
2. Enter the file's password there to produce an unlocked copy. Like the stamper, unlocking happens locally in your browser.
3. Bring the unlocked copy back to Header & footer and run it again.

The "Add header & footer" button is grayed out

Cause: both text fields are empty. The button only enables once there's something to stamp — and text that's only spaces counts as empty.

Fix:

1. Type into at least one of the two fields — Header (top of every page) or Footer (bottom of every page). You don't need both.
2. Each field takes up to 200 characters.

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

Cause: the drop zone rejects files over 100 MB to keep your browser responsive — everything happens in the tab's own memory.

Fix:

1. Split the file into parts with the Pages tool.
2. Stamp each part separately.
3. Merge the stamped parts back together in the Pages tool if you need a single file.

Some characters come out as "?" in the stamped text

Cause: the stamp is drawn with Helvetica, and text Helvetica can't encode (Cyrillic, Greek, Vietnamese and other extended-Latin characters) automatically switches to an embedded Noto Sans font. Characters outside that coverage — CJK scripts (Chinese, Japanese, Korean), emoji and some symbols — have no glyph available, so they're replaced with ? rather than producing a broken file.

Fix:

1. Reword the header or footer using covered characters (Latin, Cyrillic, Greek or Vietnamese text all render fine).
2. For unsupported scripts, use a romanized version of the text for now.

The header or footer overlaps content on the page

Cause: the line is always drawn centered, 24 pt (about a third of an inch) from the top or bottom edge, on top of whatever is already there. If your document's content runs right up to the page edge, the stamp can sit over it. There's currently no option to move it.

Fix:

1. If only one edge is crowded, put your text on the other one — a footer instead of a header, or vice versa.
2. Keep the text short, since a shorter centered line overlaps less.
3. If you need a stamp across the middle of the page instead, use the Watermark tool.

"Couldn't add the header/footer — the PDF may be corrupted or in an unsupported format."

Cause: the file couldn't be parsed and rebuilt — it may be truncated, damaged, or not actually a PDF.

Fix:

1. Re-export the PDF from the application that created it, if you can.
2. Otherwise, open the file in your browser or PDF viewer and use Print → Save as PDF to produce a clean rebuilt copy, then stamp that.

It's a scanned PDF — do I need OCR first?

No. The header and footer are drawn on top of the page, so they work on scans with no text layer at all. Run Searchable (OCR) only if you also want the scan's own contents to become selectable and searchable — the stamp doesn't require it.

Still stuck?

If none of these match what you're seeing, contact support and include what the error said — your PDF stays on your device either way, so describing the file (page count, rough size, where it came from) helps us reproduce the problem.