As from the wiki the dot product should either work for angle or real value. But isn’t working for any. I think this issue is with Synfig 1.4.1(1.4.0 also). Also it doesn’t give bad connection error just shows what is being converted to what.
(“Bad Connection” error is not displayed)
This problem occurs with 1.4.1(also on 1.4.0) I built Synfig from source it and it works fine.
And the action is failed.
Synfig version : 1.4.1
OS: Windows 10 Pro (64 bit)