When did you see this message? Did it show when updating RapidWeaver itself or your RW addons?
Please could you list which RW addons you have installed (just addons, no need for themes) or, if you would prefer, send a copy of your addons folder to email@example.com.
It displayed the message when I clicked on “Check for Updates…”.
It doesn’t display now though… Thinking it might have been an issue with Little Snitch. All these new connections rules to allow that weren’t there before.