Thank you very much for the advice, it appears to have fixed the problem! I made the changes and restarted and so far so good!
I disabled the sandbox protection and the menu bar is visible again and the caption buttons also. I have left the AcroRd32.exe as an excluded app because I forgot about unexcluding it before making the changes and I was reluctant to alter it after your method worked. The window can also be repositioned so everything seems to be normal again. Thank you very, very much!
By way of assisting anyone else I should mention that initially I thought it may be an update conflict so I switched on another computer with similar settings on WB and adobe DC and I noticed there that at start up the menu bar and caption buttons initially are normal before they then disappear. This seems consistent with your advice that something appears to be preventing then from loading correctly.
By way of a side issue I would like to say how impressed I am with Stardock programs particularly, Groupy, WindowBlinds, Start10 and Fences. My only criticism, which is really meant to be a complement, is that sometimes the aesthetics of Stardock programs do not match their functionality, performance and reliability.
Thank you also for the very prompt response!
Regards and thanks again!