Short story...
MP kept coming up on a non-existant 2nd monitor when I switched monitor setups.
Long story...
I switched computers from a dual monitor setup to a single monitor. I had switched setups and computers by cloning the hard drive to get another computer up and running. After the switch MP wouldn't load. I uninstalled MP and reinstalled the latest version. MP wanted to use the non-existent 2nd monitor. I tried right clicking on the bottom bar, hitting move, and dragging it over (that usually works), but to no avail.
Fix...
I ended up editing C:\Program Files\APM Planner\config.xml and setting <MainLocX> and <MainLocY> to zero. That worked!
I'm not sure how to fix this bug, but at least a search will hopefully find this workaround.
Replies
had the same problem and had to drag it off the second monitor each time before closing so i could use it on a single monitor