I'm getting an invalid sun declaration error using the following in an export.scn file:
# Automatic Corona scene export - main file
# comments start with #
include conf export.conf
include mtl export.mtl
include obj export.obj
camera perspective origin 83.3142 -163.965 49.4354 target 34.2329 -78.9538 30.3545 roll -0.0954056 0.165253 0.981628 fov 45
sun dirTo -0.923719 -0.28241 0.258819 color 1.78994e+006 1.21048e+006 590156 halfAngleSize 0.00445059
enviro main texmap Map#6.exr