@dstillman, it seems Zotero select links don't work correctly if they have more than about 223-227 item keys in them.

I just tested this in Zotero 5.0.88 on Windows 7, by selecting all items in Zotero and extracting their keys:

let selectedItems = ZoteroPane.getSelectedItems();
let keys = "";

for (i = 0; i < selectedItems.length; i++) {
keys = [keys, ZoteroPane.getSelectedItems()[i].libraryKey].join(",");
}

return keys.replace(/1\//g,"").replace(/^,/,"");

For my library with >2400 items, entering the zotero://select/library/items?itemKey= link in the Firefox 78.0.2 address bar only selects the first 227 items in the string. With Google Chrome 84.0.4147.89, the link silently fails (Zotero doesn't come to the foreground), unless the link is truncated to 223 items or fewer (a 223 item select string is 2044 characters).

Do you think this is a Zotero issue? https://stackoverflow.com/questions/417142/what-is-the-maximum-length-of-a-url-in-different-browsers suggests most modern browsers can handle longer URLs.

If this can't be fixed easily I can always modify Reference Extractor to chop up big select links in multiple links that each select no more than ca. 200 items.

@Rintze: Well, wait, are you just talking about trying this from browser address bars? I'm testing from a Zotero note, which works fine.

Yeah, it works for me as well with Safari/Firefox/Chrome on macOS 10.14.6. Maybe it's a Windows thing. I received this as user feedback, so it's not just me.

I'll try the Debug ID when I'm back on Windows.

(and yes, I offer users in-browser select links: https://twitter.com/rintzezelle/status/1143315626079006722)

Same problem here on Windows 10. Had to fire up my old MacBook Air and install Zotero on it in order to select my references (498 references). Good thing I had a Mac...