The DAISY Consortium has released a new version: EPUBCheck v4.2.1.
To get this update, go to the EpubCheck preferences folder (Edit > Preferences > Open Preferences Location), Edit EpubCheck.json, add/change the following entry:
save EpubCheck.json and run the EpubCheck plugin. This should initiate the auto-update code that I added in the last version, which'll automatically download the latest EPUBCheck version from the W3C Github website.