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Matti To
Matti To
Participant
February 25, 2026
Question

Catalog containing scandic letters ä and ö can generate dublicate keywords. Concersion 14>15 do not succeed.

  • February 25, 2026
  • 4 replies
  • 96 views

Bug Description

Summary

Catalog conversion from Lightroom Classic v14 to v15 consistently fails when the keyword hierarchy contains keywords starting with Scandinavian characters (ä, ö).

If all such keywords are removed in v14 prior to conversion, the catalog converts successfully to v15.

This strongly indicates a Unicode normalization or unique-index conflict during schema migration.

Environment

  • Lightroom Classic v14 (latest build)

  • Lightroom Classic v15 (latest build)

  • Windows 11

  • NTFS file system

  • Catalog size: ~2.2 GB

  • ~162,000 images

  • Large hierarchical keyword structure

  • Face recognition enabled

Exact Error Message

During conversion:

"Lightroom encountered problems when trying to update the format of the catalog file and cannot use this catalog in this version of Lightroom."

No error code is provided.

Observed Behavior

  1. The v14 catalog works perfectly.

  2. Integrity test and Optimize report no issues.

  3. All backups behave identically.

  4. Conversion to v15 always fails.

  5. Removing keywords starting with ä or ö in v14 allows the conversion to succeed.

  6. In v14 keyword hierarchy, it is possible to have:

    • Multiple keywords under the same parent

    • Visually identical names starting with ä or ö

  7. Keyword list appears internally inconsistent when Scandinavian characters are used.

Reproducible Scenario

  1. Create hierarchical keywords in v14.

  2. Use Scandinavian characters (ä, ö) at the beginning of keyword names.

  3. Allow duplicate-looking names under the same parent (visually identical).

  4. Attempt catalog conversion in v15.

  5. Conversion fails with schema update error.

Remove these keywords → conversion succeeds.

Technical Hypothesis

Likely cause:

  • Unicode normalization inconsistency (NFC vs NFD)

  • v14 allows duplicate keywords that differ only by internal Unicode representation

  • v15 schema migration likely adds or enforces a UNIQUE constraint on keyword table

  • During schema migration, duplicate normalized values cause SQLite index creation to fail

  • Lightroom reports generic conversion failure without exposing underlying SQLite error

This appears to be a schema migration validation issue rather than catalog corruption.

Impact

  • Large production catalogs cannot be upgraded

  • Scandinavian and other extended Latin character users are affected

  • No diagnostic information is provided in UI

  • Users are forced to manually delete keywords to proceed

Suggested Improvements

  1. Add proper Unicode normalization before applying UNIQUE constraints during migration.

  2. Detect and report duplicate-normalized keywords before conversion.

  3. Provide detailed error logging for catalog migration failures.

  4. Include a migration repair tool for keyword normalization conflicts.

    4 replies

    johnrellis
    johnrellis
    Legend
    March 4, 2026

    I filed this report about the failure of LR to normalize the Unicode names of keywords:

     

    johnrellis
    johnrellis
    Legend
    March 4, 2026

    I tested the second copy of the catalog you provided (with all the contents except <catalog>Previews.lrdata and <catalog>Smart Previews.lrdata), on Windows 11 running in Finnish.  The upgrade to LR 15.2 completed successfully, with no errors.  So there must be something specific to your configuration triggering the failure.

     

    Since we can’t yet reproduce this on other computers, Adobe won’t add this to their internal tracking.  But your report will remain here, in case others report similar symptoms in the future.

     

    Your testing shows the underlying problem is the failure of LR to Unicode normalization for keywords.I’ll file a bug report on that, but I’m not optimistic Adobe would prioritize a fix.

     

    Thanks for your efforts on this.

    Matti To
    Matti ToAuthor
    Participant
    March 4, 2026

    OK

     

    Matti

    johnrellis
    johnrellis
    Legend
    March 3, 2026

    Unfortunately, when I open the .lrcat you sent me in LR 15.2 / Windows 11, the upgrade to version 15 works correctly and there is no error.  I tried with LR running in English and in Swedish.  The bug could be related to something in the Helper.lrdata file (which caches keywords and other metadata).

     

    1. In which language are you running Windows?  

     

    2. In which language are you running LR?

     

    3. If you have the patience, then:

    a. Make a copy of the entire catalog folder.

    b. In the copied folder, delete the subfolders <catalog>Previews.lrdata and <catalog>Smart Previews.lrdata. (They will be too large to send and most likely not related to the bug.)

    c. Zip up the copied folder, upload it to Google Drive, and send me the sharing link. (It will probably be much larger than just the .lrcat.zip.)

     

    Matti To
    Matti ToAuthor
    Participant
    March 4, 2026

    Hopefully I copied correct files to zip, attached as a link.

    https://drive.google.com/drive/folders/1AsanO0lY8dq9OJxJXkc22wlp-HgqZNYe?usp=sharing

    johnrellis
    johnrellis
    Legend
    February 26, 2026

    I’m not able to reproduce that error during catalog conversion. I made a tiny catalog in LR 14.5.1 with the visually identical keywords “öööö” and “öööö”. The first keyword contains the Unicode codepoint U+00F6 ö (LATIN SMALL LETTER O WITH DIAERESIS), while the second keyword contains the Unicode codepoints U+006F (LATIN SMALL LETTER O) + U+0308 (COMBINING DIAERESIS).

     

    LR 15.2 successfully upgrades that catalog (on both Mac and Windows):

     

    LR has long failed to normalize Unicode consistently, e.g. see here:

     

    In general, Adobe is very unlikely to look at this problem unless you can provide an exact sequence of steps for reproducing it. In this case, if you could provide a LR 14 catalog that fails to upgrade to LR 15, they’re more likely to acknowledge the bug and track it internally.

     

    Here’s a suggested next step for providing Adobe with a reproducible test case:

     

    1. In your main catalog in LR 14, select one photo that has one instance of the keyword “Örma Seppo” and one photo with the other instance (two photos selected).

     

    2. Do File > Export As Catalog, with the options Export Selected Photos Only and Export Negative Files.

     

    3. Compress the exported catalog folder into a .zip.

     

    4. Open the exported catalog in LR 15.2.  Do you still get the upgrade error?  If so, attach the .zip file here.

    Matti To
    Matti ToAuthor
    Participant
    March 1, 2026

    Hello,

    Thank you for your quick response.

    I have been attempting to convert my catalog since late December 2025. Each time I installed the latest Lightroom Classic version 15.2 (after first uninstalling the latest 14.x version), the catalog conversion failed with the error:

    “Lightroom could not import this catalog because of unknown error.”

    This occurred regardless of how I tried to repair keywords or other metadata beforehand.

    Because of this, I repeatedly had to uninstall version 15.2, reinstall the latest 14.x version, and attempt to diagnose the issue within v14. I have spent a considerable amount of time troubleshooting this problem.

    The breakthrough came when I discovered the Any Tag keyword editor plugin online.

    For clarity:
    I have never used Any Tag previously for editing keywords. All keyword management was done exclusively using Lightroom Classic’s native keyword panel.

    Here is what I did:

    1. Using Lightroom Classic v14, I exported the full keyword hierarchy (entire catalog) with the Any Tag plugin.

    2. Without modifying the exported file in any way, I attempted to re-import the exact same keyword file back into Lightroom using Any Tag.

    3. The import failed with an error such as:

      “Any Tag > Import Keywords. Two rows (5043, 5042) with the same name (Äijälä Hilli o.s. Markkola) and same parent (4073).”

    4. I removed the reported duplicate keyword entries inside Lightroom.

    5. I exported the keyword list again with Any Tag.

    6. I attempted to re-import the unmodified exported file.

    7. The import again failed with a similar error:

      “Two rows (6501, 6500) with the same name (Nevalainen Väinö) and same parent (6104, Nevalaiset).”

    I repeated this process:

    • Remove duplicates reported by Any Tag

    • Export keyword list

    • Re-import unchanged file

    • Fix next reported duplicate

    I continued this cycle until Any Tag completed the import without reporting any duplicate-name conflicts.

    After this cleanup process:

    1. I reinstalled Lightroom Classic 15.2.

    2. I attempted catalog conversion again.

    3. The conversion succeeded.

    This confirms that the root cause was duplicate keyword entries (same name under the same parent), which Lightroom Classic v14 allowed to exist silently, but which prevented catalog schema migration in v15.2.

    It also appears that Scandinavian characters (ä, ö) may play a role, possibly due to Unicode normalization inconsistencies, since many of the problematic entries began with such characters.

    I do not intend to downgrade again, since the catalog has now been successfully converted to v15.2.

    However, I am willing to provide the original v14 catalog (containing approximately 12,000 keywords) for analysis, provided there is a secure and confidential method to transfer it.

    This issue caused a substantial amount of unnecessary troubleshooting time. It would be highly beneficial if Lightroom:

    • Detected duplicate keyword conflicts before schema migration,

    • Provided a precise error message during conversion,

    • Or included a built-in keyword integrity check tool.

    Please let me know how I may assist further.

    Kind regards,

    Matti Tossavainen

    johnrellis
    johnrellis
    Legend
    March 3, 2026

    [View this post in your web browser. It contains formatting and images that don't appear in email.]

     

    However, I am willing to provide the original v14 catalog (containing approximately 12,000 keywords) for analysis, provided there is a secure and confidential method to transfer it.

     

    In the catalog folder, zip up the .lrcat file only. Upload the .zip to Wetransfer, Dropbox, Google Drive or similar free service and send me the sharing link in a private message. To send a private message,  click “johnrellis” in the header of this reply and then click Send Message near the top. 

     

    If I can reproduce the problem, I’ll file a bug report and make the .lrcat file available to Adobe when they request it. I will of course keep that file confidential, as will Adobe.

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