Doubleclick the activity SendEmail. It will open the activity and also a popup saying that the parameters of this action have changed. You can (re)select the values for the parameters and you will be good to go.
when I double click I get an error (9.10.1)
I can rightclick and ‘go to java action’
So I'll see if I can fix it this way
ok so i've got it working
first I needed to create retrieve header:
delete the buggy action and create a new one with the following mappings
also right click and set error handeling
lastly set the bottom arrow to handle errors
or just download this microflow
https://www.dropbox.com/s/sv8xvcqr08tn21y/SF_CreateAndSendEmail.mpk?dl=0