Would suggest many problems relate build errors such as wrong part in the wrong location, wrong orientation of diodes and transistors and damaged /shorting pcb tracks; are you sure you have eliminated all of them ?
If yours is a simple diy board, suggest you run the back edge of a scalpel or similar thin blade between the tracks and component pads as that often removes any solder whiskers etc.
When getting the Vdd error, have to measured output Pin 2, do you see a voltage ? also what about across C8 , the main 5v feed when active.
What happens when you have 2.61 running (no pic chip connected to the pk2) and in 2.61 you check the VDD pk2 box on and set the voltage to 5v.
Does the Target , orange led come on and do you get +5v on the output pin 2.
If it does that ok, if you then reduce the voltage in 2.61 does output pin2 follow correctly.