MaiPDF Control Center
Troubleshooting · Diagnostics

Something is not opening. Let's work out which thing it is.

Most MaiPDF problems are not faults — they are a link doing exactly what the sender set it to do. This page shows you the exact message you are seeing, what causes it, and whether you or the sender can fix it. If none of it matches, the last section tells you what to send us.

Reader problems Sender problems Working as designed China & .cn

Start here: match what you actually see

Find your row, then read the matching card below. The right-hand column tells you who can act — a lot of these only the sender can change, because they are the one holding the modification code.

What you seeMost likely causeWho can fix it
Access link is not valid Link was truncated when pasted, pointed elsewhere by Replace, or the file passed the retention window Sender
Not authorised to view / expired page View count used up, or the expiry date has passed Sender
Asked for a code, but no mail arrives Spam folder, or your address is not on the sender's list Reader, then sender
Print or print-to-PDF comes out blank Deliberate — the reading page hides itself from printing Nobody — by design
Screenshot is black or refused (app) Deliberate — the operating system is told to exclude the window Nobody — by design
Upload refused before it starts PDF is larger than 80 MB Sender
Link works for you, not for a reader in China Wrong service — .com and .cn are separate Sender

If you were sent a link

You are the reader. Almost nothing here is under your control — but knowing which one it is saves a round of email, because you can tell the sender exactly what to change.

Reader Access link is not valid

The code does not match any file

Every MaiPDF link ends in a reading code. This message means we looked that code up and found nothing behind it.

Three things cause it. The link was cut short when it travelled through a chat app or an email client that wraps long URLs. The sender used Replace to point that link at a different file. Or the file has passed its retention window — historical files are removed roughly once every five months.

What to do: copy the link again from the original message rather than retyping it, and check nothing is missing from the end. If it still fails, ask the sender to confirm the link or re-upload.
Reader You are not authorised to view

The allowance ran out

The link is alive, but it has nothing left to give. A MaiPDF link carries a view count that drops by one every time the document is opened, and it can also carry an expiry date. When either runs out, the reader stops serving the file.

Refreshing will not help, and neither will a different browser — the count is held with the file, not in your browser.

What to do: ask the sender to raise the view count or extend the date. They can do it on the existing link with their modification code, so you do not need a new link.
Reader Verification code never arrives

Your address may not be on the list

A sender can restrict a document to a list of named addresses. Only those addresses are sent a code — anyone else is simply never mailed, with no message explaining why.

Verification mail is automated and lands in spam more often than it should, so rule that out first.

What to do: check spam and promotions folders. If it is not there, ask the sender which address they authorised — it may be a work address rather than the one you are trying.
Reader Page loads but stays empty

Usually the network, occasionally us

The reading page loads the document separately from the page itself, so a slow or filtered connection can leave you with a page frame and no document.

Corporate networks and VPNs are the usual culprits — some block the requests the reader needs.

What to do: try a different network, ideally mobile data, and a different browser. If it is empty on both, that is worth reporting — see the last section.

If you uploaded the document

You are the sender, which means you hold the modification code — and that is what almost every reader complaint eventually needs.

Sender Upload refused or never starts

Almost always file size

MaiPDF accepts PDFs up to 80 MB. Above that the upload is refused before anything is transferred, which can look like nothing happening at all.

What to do: compress the PDF — scanned documents shrink dramatically — or split it into parts and share several links.
Sender Lost the modification code

It is the only proof the link is yours

The modification code is what lets you change the view count, move the expiry date, or swap the file behind a link that has already been shared. Without it, none of that is possible.

What to do: search your inbox for the upload confirmation, and check the browser you uploaded from. If it is genuinely gone, email us from the address you uploaded with and include the reading link.
Sender Readers say the link expired too soon

The count drops on every open

The view count is consumed per open, not per person. One reader who opens the document five times uses five views. Refreshes and reopened tabs count too.

What to do: set the count generously, and check the reading records to see who actually opened it before assuming something broke.
Sender Wrong file behind a shared link

Replace, do not re-upload

If you have already sent the link out, do not create a new one. Replace points the existing link at a different file, so everyone who already has the link keeps working.

What to do: use Replace with your modification code. The link, and the reading records already attached to it, stay as they are.

Not faults — these are the point

These get reported as bugs several times a month. They are protections the sender bought by choosing MaiPDF, and they cannot be switched off from the reading side.

By design Printing comes out blank

The page hides itself from print

The reading page carries a print stylesheet that blanks the document, so browser printing and print-to-PDF both produce an empty page.

If you need a printable copy: ask the sender for the original file. There is no reader-side setting for this.
By design Screenshot is black (app)

The operating system refuses the capture

The MaiPDF app asks Windows, macOS, iOS and Android to exclude its window from screen capture. The refusal comes from the OS itself, so screen recorders and third-party capture tools hit the same wall.

Note: this is not a setting inside the app, and reinstalling will not change it.
By design A watermark you cannot remove

It is drawn at read time

The watermark is composited as the document is displayed, not baked into a downloadable file. It identifies who opened the document, which is what makes leaked copies traceable.

If it obscures the content: ask the sender — they control its appearance at upload.

Readers in mainland China

This one causes more confusion than any other single issue, and it is not a fault at either end.

maipdf.com and maipdf.cn are two separate services, on separate infrastructure, with separate databases. They are not mirrors of each other. A reading code created on one will not open on the other — the codes are not shared.

maipdf.com is the international service. maipdf.cn runs on mainland China hosting and is the one to use when your readers are inside mainland China, where cross-border connections are slow and unreliable.

If your audience is split, upload the document to both and send each group the matching link. There is no way to make one link serve both.
maipdf.com — international maipdf.cn — mainland China
Still stuck

Write to us — but send these five things

We answer faster when we do not have to ask for the basics first. A message with all five of these usually gets a real answer on the first reply.

[email protected] 
Link:        https://maipdf.com/file/……
I am the:    sender / reader
I saw:       "……"  (screenshot attached)
When:        2026-08-21 14:30, UTC+8
Browser/OS:  Chrome 141 on Windows 11
Tried:       different browser, mobile data
Never send us your modification code by email. We never need it, and it is the one thing that lets someone change your document. If you are asking us to identify a link, the reading link alone is enough.

Related reading

Background on the behaviour described above.

Delete, replace and change a shared PDF How the app protects a file How the watermark works Restricting a document to named addresses Expiry dates and view limits Sharing to readers in China