**BUG** Concise problem statement: When placed on PCB, UNO_R3 PCB footprint shows connections not made in schematic symbol. Steps to reproduce bug: Schematic and Schematic Design Manager for UNO_R3 symbol shows no pins connected. PCB and the PCB Design Manager for PCB footprint placed in PCB layout shows ratline connecting 5V **and** IOREF pins on P1! It also shows ratlines connecting AD4 to SDA and AD5 to SCL. This is not what the Schematic and the Schematic Design Manager shows!! Looking at the PCB footrint, it has been imported from Sparkfun. * The SDA and AD4 pins are assigned to a net called AD4SDA * The SCL and AD5 pins are assigned to a net called AD5SCL * The GND pins are assigned to a net called GND * The 5V and IOREF pins are assigned to a net called +5V It looks like these connections were either in the original Sparkfun footprint pin to net assignments or have somehow been introduced in the import process. * The problem must be fixed by removing the pin to net assignments leaving connections so that they must be made in the schematic and not implicitly in the symbol. That way, only what is drawn on the schematic defines the connectivity and that is also then exactly what is shown in the PCB. PLease see: https://easyeda.com/andyfierman/New_Project_161208-687269fdfa2449b993526a171c92f6d3 See also: https://easyeda.com/andyfierman/New_Project_161209_2-42e8015086ea459a8cc1340ace1bec6a Problem identified whilst investigating: https://easyeda.com/carlbenjaminsmith/Leak_Checker_Public-3d1d49e308dd46e988a69c87c4e9b983 for: https://easyeda.com/forum/topic/First_PCB_Layout-Sic6oGARL