First of all - welcome to BC ! I have been watching this topic for a couple of days in the hope that some one else would provide some help but it hasn't happened, so here goes !
Twinui. As far as I can find out this is not an application in its own right but a graphic interface and what you should be seeing is the screen of the application you are wanting to use.
However, if, for example, you are wanting to print a PDF file and you open it in Reader then, since there are no visible controls, to print it you have to use 'Ctrl+p' to initiate the printer control panel. This is ridiculous, Ctrl+P has always worked right from the days of text only DOS based displays but ever since the development of Windows 1 there has been that little printer symbol at the top of the page. Today almost nobody knows any key combination commands.
I took a PDF file up to my wife's laptop, running 8.1, and switched over to the 'Apps' view (formerly known as Metro) and found and opened 'Reader' and managed to open the file I had taken with me and got it to print using 'Ctrl+P', so try that with whatever you are trying to print.
A small complication here is that neither of us use the 'apps' on her computer - we always use the 'Desktop' view and full-fat appliications - MS Office, PDF Viewer, Irfanview, etc., etc. so I had to think about this.
If this doesn't answer your question, or if I have completely misunderstood you, post back and I will try to get someone else to have a look at it. If you do post back please include details such as which version Win 8 you are using and which applications and types of files you are having this problem with.