I have created two DNN sites using 4.9.0.
After getting the basics up and running, I created skins for them. (No, let's be honest - I did some trial & horror stuff in HTML and uploaded it as a skin...)
So mostly it works quite fine, but I have one specific problem that seems to be related to my "skin". The skin is created for a certain width, and centered on the screen. However of someone uses a browser with a smaller width, like 800 px, scrolls to the right and then drops down a menu the submenu is not aligned under the top menu item, but rather appears to the left. Sometimes so far to the left that it's outside of the visible area.
A quick test with a default skin shows that this is an issue with my "skin" rather than will DNN. However I'm at loss where to start to fix the problem. My guess is that I need to fix some CSS stuff, but what and how I don't know.
You can test the issue by going to Rotebro Scoutkår i Sollentuna , making the window smaller that the logo at the top, and then checkin out the menu in the green field.
I'm happy for any help/pointers I can get, and would be glad to make the HTML skin file available if that is of any help.