Report ID: 310673518
                    I try to perform a sync operation and Z responds with the message:
"Items in the collection 'Precipitation' have been added and/or removed in
multiple locations. The following items have been added to the collection:
...... "
Then that causes the sync to fail with this error message over and over again:
[JavaScript Error: "uncaught exception: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [mozIStorageStatement.execute]" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: chrome://zotero/content/xpcom/data/collection.js :: anonymous :: line 566" data: no] [ERROR: constraint failed]"]
                            "Items in the collection 'Precipitation' have been added and/or removed in
multiple locations. The following items have been added to the collection:
...... "
Then that causes the sync to fail with this error message over and over again:
[JavaScript Error: "uncaught exception: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [mozIStorageStatement.execute]" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: chrome://zotero/content/xpcom/data/collection.js :: anonymous :: line 566" data: no] [ERROR: constraint failed]"]
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If that doesn't do the trick, provide a Debug ID for a sync attempt that generates the error
Sync still seems to be the weak point of your otherwise wonderful Z 2.0 version. For example, I often have to do a Reset File Sync History to force the PDF attachments to get transferred. But thanks for a great piece of work.