Ok Apache, is this on a Windows, or Linux operating system?
Just to make thing easier, I would recommend renaming the existing xibo folder to something like xibo_old and placing a new copy of the xibo 1.8.1 in to a new folder called xibo. Then please make sure that Apache has full access to this folder. If on Linux, this should help. If on Windows, you really shouldn't need to do anything if you are running Apache via WAMP.
What happens currently if you open a browser and go to
Once you get an error free response from the browser on one of those then you need to make the web folder inaccessible from the internet. I can give you more instructions, but knowing the operating system first will help.
I know this seems like a giant step backwards from where you are right now, but I think getting everything correct from the install point is needed.
Something else that just hit me about your first post is:
Are you only getting the permissions problem when you log back in after being logged out? If so that is a bug that I believe has been fixed in 1.8.0, (I know it pertained to layouts, not sure about displays)