Last updated: 2026-03-23

Need help with Meridian? This guide covers common issues, troubleshooting steps, and how to contact support effectively.

Getting Help

Before contacting support, try these resources:

  1. Re-scan your archive — Many issues resolve after a fresh scan. Press Cmd+Shift+R to force a full rescan of all watched folders.
  2. Check your FITS/XISF headers — Meridian relies on standard header keywords (OBJECT, RA, DEC, INSTRUME, TELESCOP, FILTER, EXPTIME). Missing or non-standard headers are the most common cause of cataloging issues.
  3. Review this page — The Common Issues section below covers the most frequently reported problems.

If you're still stuck, we're here to help. The most effective support requests include:

  • A clear description of the problem
  • The target or file(s) involved
  • Your Meridian version (shown in Meridian > About Meridian)
  • Screenshots if the issue is visual

Common Issues

Files Not Found During Scan

Symptoms: Meridian finishes scanning but is missing files you know are there.

Try:

  1. Confirm the folder is added as a watched folder in Settings — Meridian only scans folders you've explicitly granted access to
  2. Check that files have .fits, .fit, .fts, or .xisf extensions — other formats are not scanned as light frames
  3. If files are on an external drive, make sure the drive is mounted before scanning
  4. If using iCloud Drive, offloaded (cloud-only) files cannot be scanned — download them to your Mac first

Target Not Identified Correctly

Symptoms: A target shows up with the wrong name, an obscure catalog designation (e.g., LBN instead of the common name), or as "Unidentified."

Try:

  1. Check the OBJECT keyword in your FITS headers — if capture software wrote a non-standard name, Meridian may not match it to the bundled catalog
  2. If the designation is correct but obscure, Meridian uses a popularity-ordered catalog search (Messier → NGC → IC → Caldwell → specialized catalogs) — you can manually rename the target in the Catalog view via right-click
  3. For targets with no OBJECT header, Meridian falls back to folder name parsing. Ensure your folder names contain the target designation (e.g., M31, NGC7000)
  4. For very obscure objects, enable the optional SIMBAD online lookup in Settings to attempt resolution against the full astronomical database

Duplicate Targets in Catalog

Symptoms: The same object appears as two or more separate entries (e.g., "M42" and "NGC1976", or two entries both named "M31").

Try:

  1. Right-click either entry and choose Merge to combine them manually
  2. Duplicates often arise from inconsistent OBJECT headers across sessions or capture software — Meridian normalizes most common variations automatically, but unusual spellings may slip through
  3. If coordinates differ significantly between data sets, Meridian may treat them as separate fields of the same region — this is by design for mosaic panels

Duplicate Equipment Entries

Symptoms: The same telescope or camera appears multiple times with slightly different names.

Try:

  1. This usually happens when firmware updates or capture software changes cause small header variations (e.g., "ZWO ASI2600MM Pro" vs. "ASI2600MM Pro")
  2. Select the duplicate entry, right-click, and choose Merge to combine it with the correct equipment profile
  3. Rename equipment entries to human-readable names for easier identification

Thumbnails Not Generating

Symptoms: Targets show a placeholder image instead of an auto-stretched preview.

Try:

  1. Thumbnails generate in the background after the initial header scan completes — check if the scan is still running in the toolbar
  2. If you quit Meridian during thumbnail generation, it picks up where it left off on next launch
  3. Tiled Rice/GZIP compressed FITS files (ZCMPTYPE header) are not currently supported for thumbnails — standard FITS and XISF files work fine
  4. Extremely large files or unusual bit depths may take longer to process

My Sky View Not Loading Map Tiles

Symptoms: The sky map appears black or shows only your target overlays without background imagery.

Try:

  1. Map tiles are loaded from the CDS (Centre de Données astronomiques de Strasbourg) and require an internet connection
  2. Your target overlays, coordinates, and catalog browsing all work offline — only the background survey imagery needs a connection
  3. Try switching to a different survey (DSS2, 2MASS, Mellinger) using the survey selector — some surveys may load faster depending on your connection
  4. If you're behind a firewall or VPN, ensure access to alasky.cds.unistra.fr is not blocked

Plate Solving Not Working

Symptoms: Orphaned final images aren't being matched to targets via Astrometry.net.

Try:

  1. Confirm you've entered a valid Astrometry.net API key in Settings
  2. Check your internet connection — plate solving requires sending image data to the Astrometry.net API
  3. Very wide-field or very narrow-field images may take longer to solve or fail entirely — this is an Astrometry.net limitation, not a Meridian issue
  4. Results are cached locally, so a previously solved image won't be re-submitted

Visibility Data Looks Wrong

Symptoms: Rise/set times, transit times, or altitude charts don't match your expectations.

Try:

  1. Check your observer site coordinates in Settings — all visibility calculations are driven by your active observing location
  2. If using Core Location, ensure Meridian has location permission in System Settings > Privacy & Security > Location Services
  3. You can configure multiple observing sites and switch between them — make sure the correct site is active
  4. Visibility is calculated for the current date by default

Missing Files Indicator

Symptoms: Files show a "?" indicator in the Source view.

This is expected behavior. Meridian never silently removes records when files go missing. Common causes:

  • An external drive is disconnected
  • Files were moved or deleted outside of Meridian
  • iCloud Drive offloaded files to the cloud

Reconnect the drive or restore the files, then rescan. Meridian will re-link them automatically.

Quick Look Extension Not Working

Symptoms: Pressing Space on a FITS or XISF file in Finder doesn't show a preview.

Try:

  1. The Quick Look extension installs alongside Meridian but may need to be enabled in System Settings > Extensions > Quick Look
  2. Restart Finder (Option+right-click the Finder icon in the Dock, then Relaunch)
  3. If another app has registered a Quick Look handler for FITS files, there may be a conflict

iCloud Drive Triggering Mass Downloads

Symptoms: Adding an iCloud Drive folder as a watched folder causes macOS to begin downloading all offloaded files.

Meridian scans local files only and does not intentionally trigger downloads of offloaded content. However, macOS may begin downloading files when any app accesses an iCloud-backed folder. If this is a concern, consider pointing Meridian at a local copy of your archive rather than an iCloud-synced folder.

Keyboard Shortcuts

Shortcut Action
Cmd+K Universal search across all views
Cmd+F Sidebar filter for current view
Cmd+1 / 2 / 3 / 4 Switch between Catalog, Source, My Sky, and Wish List views
Cmd+Shift+R Force rescan all watched folders
Cmd+Z / Cmd+Shift+Z Undo / Redo

System Requirements

  • macOS 14 (Sonoma) or later
  • Apple Silicon or Intel Mac
  • No internet connection required for core features

Contact Support

If you've tried the troubleshooting steps and still need help, contact us:

Email: support@macobservatory.com

Please include:

  • Your problem description and steps to reproduce
  • Meridian version (from Meridian > About Meridian)
  • The target name or files involved, if applicable
  • Screenshots if the issue is visual

We typically respond within 1–2 business days.