I was running into an issue setting up a Dynamics 365 F&O Retail Point of Sale in a UAT environment for a client and was running into all sorts of weird problems and errors. Things would work sometimes, but more often would just fail for what seemed like nonsensical reasons. Digging into each error seemed to lead me in circles. Having taken over this deployment from another developer I made the (faulty) assumption about some of the initial setup that had taken place.