# Troubleshooting

> How to deal with common problems when signing in, uploading versions, reading check results, using Ask AI, My files, the CLI and MCP.

The tables below collect common symptoms and what to do about them. If your case is not listed, message the lab head or an admin with the page link and the time of the error.

## Uploads and checks

| Symptom | What to do |
| --- | --- |
| Checks and indexing do not start | The version lacks required files (a submission needs PDF + zip). Upload the rest, or click **Chạy lại tất cả** (Rerun all) in the Issues panel |
| LaTeX compile reports Lỗi (Error) | Read the `! …` block in the finding, fix the TeX and upload a new version |
| Source ↔ submitted PDF match reports Lỗi (Error) | The PDF is scanned or has no text layer: export the PDF again from LaTeX |
| Similarity reports Chưa cấu hình (Not configured) | The admin has not entered Turnitin in [Settings → Similarity](/en/huong-dan/cai-dat/#similarity-turnitin) |
| No PDF ↔ source jump button | No trustworthy SyncTeX yet: read the reason on the PDF bar, rerun the checks or submit the PDF compiled from that exact source |
| Upload fails with 403/400 | The upload link expires after 600 seconds: try again; check the file size |
| A work created from a PDF has nothing filled in | AI is not configured or the cap was reached: use the LaTeX zip, a DOI/arXiv ID, or enter details by hand |

## Access

| Symptom | What to do |
| --- | --- |
| You cannot see your own paper | You are not a member of the work yet: ask the person in charge or the lab head to add you |
| You are sent to the 2FA setup page | Lab head accounts must turn on 2FA; follow [Sign in and 2FA](/en/huong-dan/bat-dau/#two-step-verification-2fa) |
| The invitation says it has expired | Invitations last 48 hours: ask the lab head to resend it |

## Files and Ask AI

| Symptom | What to do |
| --- | --- |
| Uploading to My files says the quota is exceeded | Delete some files (including the bin) or ask the lab head to raise your quota |
| HTML/SVG files cannot be previewed | Intentional: only PDFs, images and text are shown; other types are download-only |
| Ask AI reports `ai_budget_exceeded` | The AI cost cap was reached: ask the admin to raise the cap or change the key |
| Ask AI cannot find the content of a paper you just uploaded | Indexing has not finished: wait a few minutes and ask again |

## CLI and MCP

| Symptom | What to do |
| --- | --- |
| `papers push` reports `not_found` | The `ISL-…` code is outside your access: check the code or ask to be added to the work |
| The CLI says your sign-in has expired | Tokens last 90 days: run `papers login` again |
| The MCP client reports `invalid_client` | The client does not support CIMD: ask the admin to create a client (see [Connect MCP](/en/tich-hop/mcp/#clients-without-cimd-support)) |
| `/device` says "Mã này đã thuộc tài khoản khác" (This code belongs to another account) | Sign in with the account that requested the connection, or cancel the connection in the app and request a new code |