In November, Mozilla will release Firefox 57. This version will replace XUL with WebExtensions, this means every addon/extension not developed with the WebExtension API will stop working. The current extension for Webtop is not compatible with WebExtensions:
I wonder if OpenText will show us that they are a “software company” instead of the former Documentum owner which was a “hardware company” and have a new extension ready by the time Firefox 57 is released…
PS: I’m not even sure the extension will work on FF57, as Mozilla hasn’t implemented file access API due to security reasons, so I’m not sure if it’s even possible to port the extension to WebExtensions. (Maybe it is time for a HTML5 transfer mechanism?)