I’ve posted a “temporary fix” in Greasy Fork. It is currently unlisted because it is not intended to replace the existing script, and I’m not planning to take over development. It is only to allow people to use it until the author(s) return or a more permanent replacement can be found.
The fix involved removing the draggable markers, so some functionality is lost.
Please keep in mind this temporary version could be removed at any time. If you pass on this link to others, please let them know this as well.
https://greasyfork.org/en/scripts/26091-wme-route-speeds-mapomatic-fork
Thanks!