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Find your symptom in the sections below. Each issue starts with the quickest fix. If a section says Known Limitation, the workaround listed is the best available option.

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Alignment & Face Detection

Most common cause: Photos taken from different angles, distances, or with different chin positions between sessions.Fix:
  1. Tap the face icon to toggle alignment off, then back on — forces a fresh alignment pass.
  2. If still off, tap Manual Align to fine-tune position by hand.
  3. For future photos: use a tripod, mark the patient’s floor position, and shoot both sessions from the exact same spot.
Cause: The AI uses nose and eye positions to center the image. A slight turn between sessions shifts the centering anchor.Fix:
  1. Use the X position slider in the Crop & Zoom panel to manually re-center.
  2. Use Manual Align to lock in a position permanently.
Cause: Most common with close-up shots where the face fills most of the frame.Fix:
  1. Use the Y position slider in the Crop & Zoom panel to bring the face back into frame.
  2. For future photos: leave at least 1–2 cm above the hairline and below the chin.
Cause: At 90°, only nose and mouth are used as anchors. Any difference in chin angle or camera height creates visible misalignment.Fix:
  1. Use the Y position slider to adjust vertical alignment manually.
  2. Use Manual Align for full control.
  3. For future profiles: mark the floor with tape and use a wall reference point at nose-tip height.
Fix:
  1. Toggle alignment off, then back on.
  2. If you used Manual Align, tap Reset, then re-apply your adjustments.
  3. Navigate away and back to save the case, then export again.
Cause: The AI re-runs face detection each time and applies a small corrective rotation based on detected tilt.Fix: Use Manual Align, apply the rotation you want, and save. Manual alignment locks the transform and prevents the AI from recomputing it.

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Image Display

Cause: The image file for this case may be missing — can happen after reinstalling the app or if the photo was never imported properly.Fix:
  1. Tap the blank panel to re-import the photo from your library.
  2. If the image was deleted from Photos, you’ll need to re-photograph.
  3. Always keep a backup of patient photos in your Photos library or a cloud service — Symetri does not store images in iCloud.
Fix:
  1. Rotate the photo in the iPhone Photos app before importing into Symetri.
  2. Or use the iPhone’s native Camera app for clinical photos — it writes orientation correctly.
Fix:
  1. Export a test still and review it before presenting to a patient.
  2. If logo or handle is clipped in the export, adjust size or position in Template settings.

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Eye Blur

Cause: Eye detection failed or AI couldn’t find reliable eye positions — often due to hair over the eyes, strong shadows, or extreme angle.Fix:
  1. Use the manual position offset sliders in the eye blur panel to move the blur to the correct location.
  2. For future photos: pull hair away from the face, ensure even lighting across the eye region.
Cause: The AI detected one eye reliably but not the other — often due to shadow, slight angle, or hair/glasses on one side.Fix:
  1. Use the position sliders to center the blur between both eyes and increase blur size to cover both.
  2. For future photos: ensure both eyes are equally lit and unobstructed.
Cause: Toggling alignment or changing the treatment profile triggers a pipeline refresh that resets blur to the auto-detected position.Fix: After any major edit, go back to the Eye Blur panel and confirm position is still correct. Adjust with offset sliders if needed.

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Background Removal

Cause: Fine hair strands, wispy edges, or backlit hair are difficult for AI segmentation to separate cleanly.Photography fix: Shoot against a plain, high-contrast background. Avoid backlighting.In-app fix: Choose a background color close to the original background to blend edge artifacts.
Cause: The AI couldn’t identify a person, multiple people are in frame, or background color matches the subject’s clothing.Fix:
  1. Ensure only the patient is in frame.
  2. Ensure clothing is a different color from the background.
  3. Toggle background removal off and back on.
Cause: Background removal uses an on-device AI model. It can be slow on older iPhones or when the device is under load.Fix:
  1. Close other apps before running background removal on multiple angles.
  2. Ensure the device is charged above 20%.
  3. Known Limitation on older hardware — processing time is significantly longer on iPhone 11 and earlier.

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Export & Save

Cause: Either both images aren’t added yet, no export size is selected, or an export is already in progress.Fix:
  1. Confirm both panels have photos.
  2. Make sure at least one format is checked.
  3. Wait for any active export to finish.
Cause: Some exports fail silently if a source image is missing or a rendering error occurs.Fix:
  1. Check which files are missing — re-open that case and re-export that combination.
  2. If a case has missing images (blank panel), re-import the photos before exporting.
Fix:
  1. Go to Settings → Privacy & Security → Photos.
  2. Find Symetri and set access to Add Photos Only or Full Access.
  3. Return to Symetri and export again.
Fix:
  1. Go to Settings → Clinic Branding and confirm your logo is uploaded.
  2. In the Template panel, confirm the logo toggle is on.
  3. Check logo size — if at minimum, it may be too small to see.

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Video Export

ErrorFix
”Failed to create pixel buffer pool”Close other apps, restart Symetri, try again
”Failed to create pixel buffer”Restart the device, then export again
”Video write failed”Free up storage; check Photos permissions
”Image conversion failed”Re-open case, toggle alignment off/on, export again
Fix:
  1. Check device storage — Settings → General → iPhone Storage. Free up space if under 1 GB.
  2. Check Photos permissions.
  3. Try exporting a still first to confirm saves are working, then retry video.
Expected behavior: A typical 3-second slider video at 4:5 takes 10–30 seconds on iPhone 12+. iPhone X and older can take 40–90 seconds.Tips: Keep the device plugged in, close other apps, avoid exporting while on low battery.

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Batch Export

Cause: Cases missing before or after images are skipped automatically. Rendering failures are also skipped silently.Fix: Open each failing case individually and confirm both panels have photos before batch exporting.
Cause: Large batches hold all processed images in memory simultaneously.Fix: Export in smaller batches — select 5–6 cases at a time. Restart Symetri before starting a large batch. Keep the device plugged in.

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App Performance & Stability

Each case open runs face detection, alignment, and image processing. Give the app 5–10 seconds after opening a case before tapping edit panels. A weekly device restart keeps the system running cleanly.
Most common cause: Insufficient device memory, especially during batch export.Fix:
  1. Close all other apps.
  2. Restart the device.
  3. Export fewer cases at a time.
  4. If a specific case consistently crashes the app, re-import photos at standard resolution.
Fix:
  1. Wait 30 seconds — video export and background removal can appear frozen while processing.
  2. If still frozen, force-close: swipe up from the bottom and swipe the Symetri card up.
  3. Re-open — cases auto-save after each change and should be intact.
Go to Settings → How to Use → Replay In-App Walkthroughs at the bottom of the page. The walkthroughs will appear again the next time you open a case or enter slider mode.

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Cases & Data

Cause: Symetri stores all data locally. Deleting the app permanently deletes all case data.Prevention: Export important cases to your Photos library before deleting the app. Back up your device to iCloud before uninstalling.See Backup & Data Management for full backup instructions.
Cause: Case records were restored from backup but image files may not have been included.Fix: Re-import photos for each case by tapping the blank panel in the editor.
No. Case deletion is permanent and cannot be undone.Prevention: Export the case to your Photos library before deleting.

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Quick Fix Reference

SymptomFirst thing to try
Images misalignedToggle alignment off, then on
Face off-centerAdjust X/Y position sliders
Face off-frameUse Y slider; check source photo framing
Eye blur in wrong spotUse manual offset sliders in Eye Blur panel
Background removal has halosReshoot on plain neutral background
Export button greyed outConfirm both before & after images are imported
Export missing filesCheck disk space; check Photos permissions
Video export errorRestart app; close other apps; retry
App crash during batchExport fewer cases at a time; restart device
Case images blankRe-import photos; check if app was reinstalled
White edges when panningIncrease zoom before panning
Walkthroughs not showingSettings → How to Use → Replay Walkthroughs