I was able to reproduce this error. Seems Oxygen does not like downloading stuff from SourceForge. I changed the download site (yes, I know, evil hackery) in the released updateSite.oxygen file to the GitHub one, and it became happy again. I think we'll need to change the release building process accordingly. I did report the failure to download to Oxygen, so it's possible they may fix it. It sounds like there's a bunch of updating work to be done for the plugin anyway, given the failure to build with newer versions of Oxygen. Anyway, this is "fixed" for now, but will be broken again as soon as we do a new release, if we don't change it. Hugh ---------- Forwarded message ---------- From: Huskey, Samuel J. Date: Tue, Jul 11, 2017 at 11:08 AM Subject: Heads up To: Hugh Cayless Dear Hugh, Oxygen is complaining about the new update to the TEI add-on. When I tried to apply it, it did this: Clicking on “More details …” gives me this: I went to https://www.oxygenxml.com/doc/versions/19.0/ug-editor/ topics/import-https-server-certificate.html?hl=https%2Ctroubleshooting as instructed. That was *not* helpful, so I’m coming to you for advice about what to do. Best, Sam