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Document Scanner Preview Is Frozen

Quick Fix

Most fixes take under 5 minutes. On iPhone and iPad, a healthy preview should stay open without refreshing. If the scanner stays on “Initializing camera…”, wait up to 15 seconds. Then select Retry when it appears.

Use this guide when the camera view in Document Upload stops moving during check-in. AVA automatically recovers common camera pauses. If you leave Document Upload while the camera starts, AVA releases the camera before you reopen it. On iPhone and iPad, AVA does not refresh a healthy preview from frame-count checks. This includes iPads using desktop-mode browsing.

Quick Reference​

What you seeWhy it happensWhat to do
iPhone or iPad preview stays open while the document movesThe preview is healthyContinue scanning; no refresh is needed
Preview freezes after screen lockThe device paused the camera while the scanner stayed openUnlock the device and wait for AVA to resume the preview
Preview stays on one imageThe camera stopped delivering new framesWait for recovery, then use Retry if shown
Camera stays unavailable after leaving the scannerCamera startup finished after the scanner closedReopen Document Upload and scan again
Scanner stays on “Initializing camera…”Camera startup did not finishWait up to 15 seconds, then select Retry
Camera error appears during a scanThe camera is temporarily unavailable, busy, or interruptedWait for automatic recovery, then use scanner-only Retry
Camera permission is deniedThe device did not grant camera accessAllow camera access in device settings, then reopen the scanner
Preview freezes again on the same deviceThe camera is still unstableRestart the device and contact support
Android kiosk stays green on "Hold steady"The capture needs recovery or the kiosk has an older app sessionReload the kiosk app, then scan again
Custom scanner stays on “Hold very still”The scanner changed to a different document outlineRestart Document Upload, then scan again
Android shows a blank viewfinder or camera startup messageThe camera permission, another app, or camera initialization blocked startupFollow Android camera startup fixes

Android camera does not start​

What you see: The Android viewfinder is blank, or AVA shows a camera startup message.

AVA may show camera guidance instead of a document-upload error when the camera cannot start. No document upload occurs until the camera starts successfully. Automatic recovery retries temporary failures without reloading the guest journey.

Fix:

  1. If AVA asks for camera access, choose Allow.

  2. Close other camera apps and duplicate AVA tabs.

  3. Wait for AVA to retry the camera.

  4. If Retry appears, select it once.

  5. If the message says the camera is in use, close other camera apps.

  6. Reopen Document Upload only if the scanner stays unavailable.

  7. Use another kiosk or tablet if the camera still cannot start.

    ✓ The viewfinder should show a live camera image before you scan.

Android kiosk stays on “Hold steady”​

What you see: An Android kiosk shows a green Hold steady message for 10–20 seconds.

Fix:

  1. Keep the document inside the guide and hold it steady.

  2. If the kiosk recently received an app update, reload the kiosk app.

  3. Wait for automatic camera recovery.

  4. Select Retry if AVA shows it.

  5. Scan the document again.

    ✓ The scanner should capture normally without a long green-screen delay.

The updated scanner automatically recovers failed captures and restarts the camera. Automatic recovery keeps the current guest journey and unsaved fields. You do not need to change scanner thresholds or security settings.

If the scanner still stays green after reloading the app, follow Preview keeps showing the same frame.

Custom scanner stays on “Hold very still”​

What you see: The custom scanner keeps showing “Hold very still” after the document outline changes.

AVA now clears older sharpness samples when it selects a different document outline. This prevents an earlier sharp area from blocking capture of the full document.

Fix:

  1. Keep the complete document inside the guide.

  2. Hold the device steady under even lighting.

  3. Close Document Upload and reopen it if the message remains.

  4. Scan the document again.

  5. Contact support if clear documents remain blocked after restarting the scan.

    ✓ The scanner should capture without changing security settings or thresholds.

Camera stays on “Initializing camera…”​

What you see: The scanner shows “Initializing camera…” for longer than expected.

AVA now ends a stalled camera start after about 15 seconds when permission is available. A pending permission prompt can keep the scanner waiting until you answer it.

Fix:

  1. Keep the current check-in screen open for up to 15 seconds.

  2. Select Retry when AVA shows it.

  3. Allow camera access if your device or browser asks.

  4. On a kiosk iPad, set camera access to Allow for the AVA site.

  5. Close and reopen Document Upload if the camera remains unavailable.

  6. Restart the device if the same problem returns.

    ✓ The scanner should show a live preview without restarting the full check-in.

If the scanner still cannot start, use another kiosk or tablet and contact support.

Camera stays unavailable after leaving the scanner​

What you see: You leave Document Upload during camera startup, then the next scan cannot use the camera.

AVA cancels the previous startup and closes a camera that opens after you leave. You should not need to reload the entire check-in page.

Fix:

  1. Wait a few seconds after leaving Document Upload.

  2. Reopen Document Upload.

  3. Select Retry if AVA shows it.

  4. Scan the document again.

  5. Close other camera apps or duplicate AVA tabs if the camera remains unavailable.

    ✓ The scanner should show a live preview without a full-page reload.

If the camera still cannot start, restart the device and use another kiosk or tablet.

iPhone or iPad preview stays open​

What you see: The preview stays open while the guest moves the document.

Fix:

  1. Continue positioning the document inside the frame.

  2. Wait for the document capture to complete.

    ✓ AVA keeps a healthy iPhone or iPad preview open while you scan.

Preview froze after screen lock​

What you see: The scanner shows the last frame after you unlock the device.

Fix:

  1. Unlock the device.

  2. Wait up to 5 seconds.

  3. Do not switch screens yet.

  4. If the preview still looks frozen, close Document Upload.

  5. Reopen Document Upload and scan again.

    ✓ The camera preview should move again before the next scan.

Preview keeps showing the same frame​

What you see: The scanner stays open, but the image does not change.

Fix:

  1. Wait for AVA to detect a stalled preview.

  2. Select scanner-only Retry when it appears.

  3. Try the scan again.

  4. If Retry does not restore the preview, close and reopen the scanner.

  5. If the issue repeats, restart the device.

  6. Use another kiosk or tablet if available.

    ✓ A healthy camera should show a live preview again.

Why this can happen

Some devices pause the camera when the screen locks. A camera stall can also stop new frames without closing the scanner. AVA retries paused-video recovery across platforms. Android also uses frozen-preview recovery. iPhone and iPad do not use frame-count checks because those values can be unreliable.

The camera error keeps returning​

What you see: AVA cannot recover the camera automatically, or Retry does not help.

Fix:

  1. Keep the guest on the current check-in screen.
  2. Select scanner-only Retry once.
  3. Confirm no other app is using the camera.
  4. Check that the device still allows camera access.
  5. Close and reopen the scanner if AVA still shows the error.
  6. Use another kiosk or tablet when available.

✓ The guest's completed steps and current journey remain available.

Permission denials need a setting change

AVA does not repeatedly retry a denied camera permission. Allow camera access in the device or browser settings, then reopen the scanner.

Still Stuck?​

Contact success@vouch-technologies.com if:

  • ❌ The preview stays frozen after you reopen the scanner
  • ❌ The same device freezes every time
  • ❌ The guest cannot continue check-in after a restart

Helpful details to share:

  • Device model
  • Browser version
  • Whether the screen locked first
  • Time the issue started