Error saying solarspectrum3 not resolved from current namespace SolarSpectrum

Question

I get the following error when I call a function.

Error in .C("solarspectrum3", as.double(lon), as.double(lat), as.double(timezone),  : 
  "solarspectrum3" not resolved from current namespace (SolarSpectrum)

Answer 1

the call to .C() or .Call() needs to be amended in the package's source, to include PACKAGE = "name_of_dll_without_extension".