I am giving TeXStudio (2.10.2) a whirl on Mac OS X 10.10.5. I'm trying to setup an external PDF viewer using a TeXStudio Command. I have tried to set it up with this:
I also have Acrobat installed but there is no need to open that (it is now the default) merely to print a file, so I have specified Preview specifically.
Using Tools>Commands>View PDF gives no error, but only opens the internal viewer in a separate window.
I have searched the documentation and this site, but so far nothing. TeXStudio is a nice environment, and I must be missing something basic.
I just noticed that by clicking on the 'External viewer' button on the internal viewer window works.