Hi, everyone. I am running Dorico 4 (trial) on a Windows 10 machine. I have an external monitor, and when I work on it, drop-downs (such as the Full score drop-down) don’t show when opened. The primary window color and buttons both change color, so I know Dorico thinks the item is opening, but I can’t see the drop-down part of it (I’ll note here that the menus open fine). I’ve tried changing the display resolution, none fixes it. Neither does changing the zoom (“Change the size of text, apps, and other items”). Any suggestions? I really want to purchase this product but if I can’t work effectively on a large monitor, it’s kind of a deal-breaker.
Welcome to the forum, Karin. Yes, this is a known problem with the Qt application framework when you have multiple monitors with different sizes/resolutions/scale factors. I believe you might be able to see the drop-downs if you designate your external monitor as the primary display on your system.
There are other ways of accessing different layouts, as well: you can switch to a part layout by selecting an item belonging to the player whose part you want to view, then type W (the shortcut for Window > Counterpart Layout), and you can also cycle through the different layouts using the shortcuts for Window > Next/Previous Layout (which escape me temporarily).
Thanks for your quick reply! I did set the external monitor as my main display and that didn’t fix it. Weirdly, once I did that, the Full score menu stopped working on my laptop display, so I changed my laptop back to the primary monitor, and now the menu works on my large monitor.
Key command is Alt+Shift+[ or ] to cycle through layouts, which is all I need really.
Now to go figure out why I can’t hear playback. 
See this thread, including a textual transcript of the video, in case you find that useful:
Thanks! After I wrote my post I found that video and was able to fix my audio issue. Great video, although it’s a bit dated – the downloads it recommends are from version 1 from what I could tell, and the file naming has changed. Thanks for the link though. It took me a while to find the video so hopefully this will help others. I would also recommend checking out the frequently asked questions post in the pinned forum posts marked for newcomers to the forum.