Hi,
I have just installed Dorico 5 SE on Mac and there is no Scrob playback toolbar button…
Why? 
Do I have to install the Dorico Elements or Pro; have searched the stainberg web for info…but I am still lost.
Thank you very much
Welcome.
Scrub playback is not available on Dorico SE.
SE is useful, but lacks many of the features of Elements/Pro.