Skip to main content

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 preview stops moving, unlock the device and wait a few seconds.

Use this guide when the camera view in Document Upload stops moving during check-in. AVA automatically recovers common camera pauses. 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 framesClose Document Upload and start the scan again
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
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.

Fix:

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

  2. Close other camera apps and duplicate AVA tabs.

  3. Close Document Upload, then open it again.

  4. If the message says the camera is in use, restart the Android device.

  5. Reopen AVA and start the scan again.

  6. 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. Close Document Upload, then open it again.

  4. 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. 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.

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. Close the scanner.

  2. Reopen the document scan flow.

  3. Try the scan again.

  4. If the issue repeats, restart the device.

  5. 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.

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