This is not a problem of the gerber import. This is a problem with your installation.
(You will get the same error when opening pcbnew for a kicad project.)
What operating system are you using and how did you install kicad.
Also be warned: the gerber viewer to pcb_new export does not really work.
(At least it does not in the stable kicad version i have not checked it under nightly)
Issues i discovered with it:
- pads are changed to vias (even smd pads)
- copper zones are not created correctly. (The outline is traced with short tracks instead. No copper zone is created.)
- in my tests i found no way to get npth holes imported.
Maybe somebody knows of a workaround for all of that.
I edited your title to indicate that you want to import from altium to kicad.