On my start menu I have a scroll view to display the levels in my game:
It works fine in the editor every time but acts weird in builds. As a windows 10 app the scroll bar isn’t visible and there are no restraints on the scrolling (so you can keep scrolling until all of the content is off the screen) also sometimes it flashes and even disappears altogether. On WP 8.1 the scrollbar is there and the restraints work fine but sometimes when I load the start menu the backgrounds are merged in a weird way, the title disappears and when play is tapped the scroll view doesn’t appear at all:
The problem is not with resolution as I have checked this in the editor and it works fine for all resolutions.
How do I fix it?
I’ve had similar issue. The problem was that Scroll bar mode “Auto hide and expand viewport” wasn’t working on WebGL builds.
Got it!, You have to create the menu in run time to avoid this error, for some weird reason it does not create the content when you have it “Pre-loaded” in the editor, so either create the menu in real time or instantiate a prefab of the full menu, it worked for me that way.
I’ve been fighting the same (or similar) issue. In my case it seems like the “Content size fitter” atteched to the content game object of the scrollview somehow screwed things up when building for desktop.
After creating a new scrollviews a few times I finally ended up with one that worked by adding one setting or component at a time. I am not sure what the illegal setting was that made the scrollview not work in the build and now that I have a working version I’m not touching it 
In Your Scroll Rect component set the Visibility to Permanent.
It Should Work.
In my project, the same error was occurring. After a thorough investigation, I found the point that was causing the error in the UI.
In one of my scripts, there was a frame controller
Application.targetFrameRate = 300;
So, I commented it out, and the error stopped.
