# Troubleshooting

> The problems you may meet, and how to fix each one.

Start at **Settings → Books & Shelves → Library**. **Connections** says what the plugin can reach.

## Calibre shows as off or not reachable

**Why:** the Content Server isn't running, or the address is wrong.
**Fix:** in Calibre, select **Connect/share → Start Content server**. Then select **Connect…**, check the **Content Server address** and select **Test**.

## The library reads but changes aren't written

**Why:** the Content Server doesn't allow this connection to make changes. The Library tab says *Connected, read-only*, and **Connect… → Test** fails the *Changes* check.
**Fix:** in Calibre, **Preferences → Sharing over the net → Advanced → Allow un-authenticated local connections to make changes**, **Apply**, then stop and start the server. Or enter a **User** and **Password** that may make changes. See [the settings Calibre needs](connect-to-calibre.md#the-settings-calibre-needs).

## The library is read-only

**Why:** the server is off, and the library is being read from its folder instead.
**Fix:** start the Content Server. Until then, syncing notes works, and book files and writes wait.

## A change shows as a conflict in the write queue

**Why:** the value changed in Calibre after the change was proposed, so it wasn't written.
**Fix:** look at the book in Calibre. Reject the change, or look the book up again to propose a fresh one.

## A sync lists books it couldn't place

**Why:** more than one note could be the book, or the match isn't certain. It lists these and doesn't guess.
**Fix:** add the book's Calibre id or ISBN to the right note's properties, then sync again.

## No covers come from Google Books

**Why:** Google gives no covers without an API key.
**Fix:** add a **Google Books API key** on the **Notes** tab, or rely on Calibre and Open Library.

## "This plugin needs Model Hub…"

**Why:** Model Hub is missing, turned off or too old.
**Fix:** install, enable or update Model Hub. Syncing notes and covers works without it; shelves, summaries and lookups need it.

## A job has made no progress for five minutes

**Why:** a call is slow or stuck.
**Fix:** wait, or cancel it from **Books & Shelves: Open the jobs view**.

## A run stopped at a limit

**Why:** a call was billed well above its listed price, or one of Model Hub's limits was reached.
**Fix:** check Model Hub's usage view and the tier's limits, then run it again.

## A pack isn't used

**Why:** its `pack.yml` has a mistake. A notice names the pack and the problem.
**Fix:** correct the file and run **Reload packs**.

## Questions

### Does it change my Calibre library?

Only through the write queue, after you accept a change, and when you agree to an EPUB conversion. See [Changes to Calibre, and undo](changes-to-calibre.md).

### Does it work on mobile?

No. Books & Shelves is desktop only for now.

Still stuck? See [Getting help](https://github.com/Insurgent-Methods/books-and-shelves/blob/HEAD/SUPPORT.md).