Blank screen when opening process in Workbench

Back to working with LiveCycle ES2 on a new project and had problems opening any process after installed Workbench ES2 on my laptop.  When opening a process in Workbench ES2 I was being shown a grey tab with no content.  The workaround seems to be to run Workbench as an Administrator (right click on icon > Run as Administrator).  Solved the problem but don't know why it needs it!