I have read other answers so similar questions about this but they had project items at different levels but I don't.
My project is structured as follows:
Windows\ contains xaml for windows
UserControls\ contains xaml for user controls
Images\ contains .png files
My program all runs fine and correct at run time.
When I am including images into xaml I am doing it like this:
<Image Source="/Images/ImageName.png" />
At design time when I use an image in a window it shows up fine.
At design time when I use an image in a user control is shows up fine.
At design time when I put a user control containing an image in a window it just shows a red X and gives the error:
Cannot locate resource images/imageName.png. At run time of course this window displays just fine.
(Just an observation note also: the first char of the image name has been lower cased in the error message).