I'm having issues after creating and deleting artboards where layers within artboards can't be edited with a warning that says that the element is hidden. However I've never seen this with a red transparent issue and if I isolate this element cmd+t I'm able to scale the object and move it like it's a real element. However it's not showing in my layers and it's not hidden within the layers either.
You are in Quick Mask mode (see the tab at the top of your document and your layers highlighted in red). Press Q on your keyboard to come out of it
Can't even believe I never noticed this! WOW that's what happens when you get into a rush!