Hello,

I am experiencing the same synchronization problem after upgrading Zotero.

Environment:
- Zotero 10.0.2 (64-bit)
- Windows 11
- Personal library
- The affected records are recently imported PDF attachments
- These attachments use linked-file mode
- Their parent bibliographic items are present and mostly synchronized
- The original PDF files still exist locally

Synchronization repeatedly reports errors such as:

'7KP5ROTQ' is not a valid item key

After another synchronization attempt, the error changed to:

'2F97NBK0' is not a valid item key

The error may change to another attachment key after each attempt, which suggests that multiple recent attachment records are affected rather than only one item.

I also tested Zotero Troubleshooting Mode, but the same error remained. The LLM-for-Zotero plugin is disabled. I have not used “Reset Sync”, and I do not want to delete the original PDF files.

Could you please advise:

1. What causes these attachment keys to be reported as invalid?
2. Is there an official batch-repair method for the affected attachment records?
3. Can the records be repaired while preserving the original linked PDF files?
4. Is there a safe procedure that avoids resetting synchronization or manually recreating every attachment?

I can provide a sanitized debug log or additional diagnostic information if needed.

Thank you.

@adamsmith Thank you for pointing me to that discussion. I followed the link and read it carefully.

However, I am not sure that it applies directly to my case. The linked discussion suggests that invalid item keys may have been created by a plugin or AI tool, and mentions deleting the invalid items or rebuilding the local database. In my case, the error appears to involve a recent linked-file PDF attachment that still exists in my local Zotero library, and the original PDF file is still present on my computer.

I am using Zotero 10.0.2 on Windows 11. The sync error is:

“2F97NBK0 is not a valid item key”

I previously also received:

“7KP5ROTQ is not a valid item key”

The error still occurs in Troubleshooting Mode. I have disabled the LLM-for-Zotero plugin. I have not used Reset Sync, deleted my local database, deleted the original PDF files, or emptied the Zotero Trash.

I also tried the CLI Bridge mentioned in the discussion, but the available Bridge plugin is incompatible with Zotero 10.0.2.

Therefore, the suggested database deletion or broad removal of items does not seem safe or directly applicable to my situation. Could you please advise me how to identify the specific invalid record and repair or remove only that record while preserving the local PDF files and other unsynced data?

Thank you.