---
id: KB-PR-005
url: https://app.codecontract.io/help/troubleshooting/i-cannot-upload-a-file
idioma: en
categoria: problemas
audiencia: usuario
nivel: intermedio
actualizado: 2026-08-13
tambienEn: [es]
relacionados: [KB-DI-003, KB-PR-001]
citadoPor: [KB-DI-007, KB-PR-009, KB-PR-015, KB-PR-022]
---

# I cannot upload a file

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

**Responde a:** error uploading a document · the upload stalls halfway · it will not accept my file · the pdf will not upload

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

| Symptom | Likely cause | Fix |
| --- | --- | --- |
| Stops at 90% and goes no further | Unstable connection | Retry on wifi or cable; the upload resumes where it was |
| Says it is too large | Over 30 MB | Rescan at 300 dpi or split the document |
| Says the file is not valid | It is damaged or an unusual format | Open it first: if your computer cannot either, the file is broken |
| Nothing happens when clicking | A browser blocker | Try 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.

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

> [!WARNING]
> 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.

## Ejemplos

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

- Rescans at 300 dpi in greyscale

→ It drops to 11 MB and uploads first time.

**The upload cuts out halfway on an unstable connection.**

- Retries from a stable network

→ The file goes in without splitting anything.

**The file is over the size limit.**

- Compresses or splits the document

→ It uploads without losing content.

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

- Uploads the files, not the folder

→ The error disappears without changing browser.

**The file name contains unusual characters.**

- Renames it before uploading

→ The upload stops failing for no apparent reason.

**Upload happens from a phone and the app closes.**

- Retries with the screen awake until it finishes

→ The upload completes first time.