Endnote continuously adds same reference to library to the point of rendering the library unusable

My Endnote library strangely continuously, with no end, keeps on uploading the same reference to it. So far it is uploaded it over 60,000 times in less than an hour and has not stopped. The process of doing so creates intense lag to the point of rendering the library unuseable (I can’t even delete one of those copies!, and in the process of trying, thousands more are added to the library). I think Endnote is trying to sync the library at the same time.

None of these continuous reference copies are present on the library when viewing it on EndNote online or on my iPad.

I had added the reference some weeks ago, but have used the library since without problem. This only occurred today evening, even after using it in the afternoon without issues. I did not attempt to upload that reference in that afternoon.

Opening and closing Endnote makes no difference. The EndNote library is on my Dropbox, and strangely the references remain when upload an older version from a few days from Dropbox, even when those duplicate references were not present then. This is using Endnote X9.2 on a MacBook Pro (Retina, 13-inch, Early 2013) with macOS Mojave version 10.14.6.

Any help would be appreciated, as otherwise I’ll be unable to use this library on my computer. 

Please contact Technical Support directly

1-800-336-4474 option 4 then 1



We are here to help whenever you run into issues.

Hi Tony,

I have the same problem, but can’t reach your service number from austria. Is there a chance to get in touch via e-mail?



Kathi L

I encountered the same issue in EndNote 20.1. When I attempted the sync my library to EndNote Online, it started downloading thousands of copies of one of my references.

I was able to stop the downloads by going to Preferences: Sync: and turning OFF the Sync Automatically option, and then quitting EndNote. When I restarted the program, the Sync did not start, and I was then able to delete the thousands of extra copies of the reference.

If I start another Sync, the problem recurs. Thus, EndNote Sync is broken for me. But I’m able to use the library and use other services for backup.