It's a pretty common problem for some Marlin printers out there to not reach proper bed temperature (a degree to two less than the set requirement). This will cause Simplify3D to never print (it just sits for hours trying to heat the bed another degree.
In order to get printing automated (bed temp actually get the temp it should get to) I would like to see the following setting added:
Bed Temp Fudge Factor: [---] C.
If I was to set this to "2"; and if my printer actually says its actually 118 instead of 120 Simplify3D will actually start to print.