FMP16; Windows 7
1) From layout mode, double click an existing button
2) on the button setup, click the script name
3) click into one of the script's step's inline editing field (on an IF or ELSEIF, for example)
4) check your email
5) go back to FileMaker
RESULT: the button setup window can be seen, but not the modal script window. Switching programs a few times and then coming back to FM16 seems to work after one or two tries.