newbie of hfss needs help

Hi, when i try to save a project I receive an error,
Project7
[error] An error occurred while writing to file Project7.hfss. Is the file or directory read only? Disk Full? (7:51 Dec 12, 2010)

Neither file nor directory is read only or full. Why is this happening?

Sometimes it is not your fault, but the software itself. When I meet similar problems, I usually save the file as another name and restart HFSS. My solution may not be the most effective but it works. Hope it helps.

Thanks for advice, I maintained the problem. The directory that I try to save *.hfss file had some spesific non-english characters. I received no errors when I changed the directory.