HI! I checked out the post and while trying to find out how to do a solution I accidentally stumbled on my own solution.

I was trying to enable the reading pane by right clicking in the message bar area. ( on the right side above the actual messages, " From", "Subject", "Received" ect.. and then navigated to "Customized current view".

I solved the problem by going straight to the top menu bar and selecting "View" then "Reading Pane" ->bottom.

There must be a bug when trying to change the reading pane the other way.

Paul