Did you use the same model library in other simulation environments, hspice for example?
If the model can be used with hspice but not nanosim, it is strange.
But if hspice can not read the model either, you may see which line cause the syntax error. There may be some typo.
If the OS is UNIX, you should check the model file is in UNIX format. The DOS/Windows format has a carriage return at the end of each line, which displayed as ^M in vi.