Saltar al contenido

Troubleshooting

I cannot upload a file

It stalls, errors, or refuses the file: the causes by frequency.

Updated on 13/08/2026

It is nearly always size or connection. Before going in circles, check these four in order.

SymptomLikely causeFix
Stops at 90% and goes no furtherUnstable connectionRetry on wifi or cable; the upload resumes where it was
Says it is too largeOver 30 MBRescan at 300 dpi or split the document
Says the file is not validIt is damaged or an unusual formatOpen it first: if your computer cannot either, the file is broken
Nothing happens when clickingA browser blockerTry another window or another browser

If the file is damaged

A PDF that will not open on your computer will not upload either. It usually happens when a file was half-copied from a USB stick or downloaded from an interrupted email. Ask for it again: there is no way to recover it from here.

Worth knowing

Uploading twenty files at once over a slow connection fails more than uploading five at a time. On a poor connection, go in batches.

Watch out

If a file was rejected on security grounds, do not retry or rename it: it means there is something inside that should not be. Check where it came from first.

Is progress lost if it cuts out halfway?

No, it resumes. It is only lost if you close the tab.

Can I upload from a phone?

Yes, including photos taken on the spot.

Is there a limit on how many at once?

Practical, not technical: the more there are, the longer it takes and the likelier the connection fails.

A real case

The situation

An administrator cannot upload a 60 MB scan of a deed.

What you do

  1. Rescans at 300 dpi in greyscale

What you get

It drops to 11 MB and uploads first time.

The situation

The upload cuts out halfway on an unstable connection.

What you do

  1. Retries from a stable network

What you get

The file goes in without splitting anything.

The situation

The file is over the size limit.

What you do

  1. Compresses or splits the document

What you get

It uploads without losing content.

The situation

An attempt is made to upload a whole folder at once.

What you do

  1. Uploads the files, not the folder

What you get

The error disappears without changing browser.

The situation

The file name contains unusual characters.

What you do

  1. Renames it before uploading

What you get

The upload stops failing for no apparent reason.

The situation

Upload happens from a phone and the app closes.

What you do

  1. Retries with the screen awake until it finishes

What you get

The upload completes first time.

This article answers

  • error uploading a document
  • the upload stalls halfway
  • it will not accept my file
  • the pdf will not upload