One thing that people could try is to take the 0.3.1 JAR file from the add-on message and place it in the addons folder of their installation.
I just did that on a blank installation and it did not trigger any errors in the log, while being able to add the bridge and a forecast thing which started receiving values.
I haven’t done further testing just yet, but I would appreciate if people could do this experiment as well and report back here.