I have version 5.0 of Autosketch which I thought is what the drawing was created with. When I attempt to open the .SKF file I get the error message "unexpected file format". I click on OK since it's my only choice. The software is open not the file. So then I attempt to use the open file option. I drill down to the file location and it shows in the preview pane but does not allow it to be opened, showing the same error. Not sure what version the drawing was originally created in (i.e. 6.0, NOT 7 - 8). Need to know that some version of Autosketch will be able to open this even if it is version 8.0 before I buy it. Any help would be appreciated.