[JavaScript Error: "TypeError: Cannot read property 'length' of undefined

Hello,

[JavaScript Error: "Upload request 1/ZATZR8YV failed"]

Thanks a lot. Would you please paste the whole codes?

From that page, I know I can add condition,

[JavaScript Error: "TypeError: this.titleCaseLowerCase is undefined" {file: "chrome://zotero/content/xpcom/translation/translate_firefox.js line 425 > eval" line: 1273}]

[JavaScript Error: "XML Paring Error: not well-formed etc.

The codes are from https://www.zotero.org/support/dev/client_coding/javascript_api

Can you select the parent item, paste this into Tools → Developer → Run JavaScript, and tell me the result?

[JavaScript Warning: "unreachable code after return statement" {file: "resource://zotero/loader.jsm -> resource://zotero/bluebird/util.js" line: 205 column 4 source: " eval(obj);

[JavaScript Error: "Download request 1/7Y9DTXT5 failed"]

[JavaScript Error: "Error: URL changed for tab https://mail.google.com/mail/u/1/#inbox

[JavaScript Error: "TypeError: Cannot read property 'length' of undefined

[JavaScript Error: "Download request 3/Y43YILFD failed"]

Thanks for the clarifications. I might give this a try once the broken relations import is fixed. Since I have almost no programming knowledge (especially not in javascript), so I would need to start

[JavaScript Error: "creatorID not provided" {file: "chrome://zotero/content/xpcom/data/creators.js" line: 69}]

[JavaScript Error: "Request timed out"]

[JavaScript Error: "Cannot move collection into itself!" {file: "chrome://zotero/content/xpcom/data/collection.js" line: 258}]

[JavaScript Error: "HTTP POST https://api.zotero.org/users/4466723/items/LWL3AKIY/file failed with status code 400:

[JavaScript Error: "Request timed out"]