The scanner won’t work / freezes / camera is black

If the Scan tab shows a black screen, won’t recognize barcodes, or is otherwise frozen, here’s how to diagnose and fix.

Step 1 — Check camera permission

Manga Vault needs camera permission to scan barcodes.

iOS

1. Open Settings on your iPhone.
2. Scroll to Manga Vault.
3. Tap Camera and ensure it’s set to On (or Allow Access).

Android

1. Open Settings → Apps → Manga Vault → Permissions.
2. Tap Camera and ensure it’s allowed.

If permission was denied, the Scan tab will show a “Camera access required” message with an Open Settings button. Tap it for a direct deep-link to the right page.

Step 2 — Force-close and reopen Manga Vault

Sometimes the camera service gets stuck. Closing and reopening the app usually fixes it.

iOS

Swipe up from the bottom of the screen (or double-press Home on older devices) to open the app switcher, swipe up on Manga Vault to close it, then re-open it.

Android

Tap the recents button, swipe Manga Vault away, then re-open.

Step 3 — Close other camera apps

If another app is currently using your camera (Zoom, FaceTime, the Camera app), Manga Vault may not get access. Close those apps first.

Step 4 — Restart your phone

If the scanner is still acting up:

1. Restart your phone (turn off and back on).
2. Open Manga Vault.
3. Try scanning.

A restart clears most camera service issues.

Step 5 — Clean your camera lens

If barcodes aren’t being recognized but the camera is showing a clear image, the lens might just be smudged. Wipe it with a clean cloth.

Specific symptoms

Black screen, no preview

Usually a permission issue. Check Step 1.

Camera shows but barcodes aren’t detected

• Hold the volume steadier.
• Try better lighting (turn on the in-app torch if available).
• Make sure the barcode is fully in the scan frame.
• Try manual ISBN entry as a fallback.

Scanner detects but nothing happens

The result modal should appear within a second of detection. If it doesn’t:

• Force-close and reopen.
• Check internet (we look up the ISBN against the catalog).

Scanner works briefly then freezes

This sometimes happens during long scanning sessions due to camera thermal management. Take a break, let your phone cool, and try again.

Step 6 — Reinstall as a last resort

If nothing else works:

1. Sign out of Manga Vault (Settings → Sign Out).
2. Delete the app.
3. Reinstall from App Store / Play Store.
4. Sign back in.

You won’t lose data — your collection, friends, and settings are all in the cloud.

Still not working?

Contact support with:

• Your phone model and OS version.
• Manga Vault App Version (Settings → About).
• A description of the symptom.
• Whether the issue happens on a specific volume or all volumes.

Tip

For occasional barcode trouble, manual ISBN entry is always available as a fallback. See Entering an ISBN manually.