By default, .EPS files are supported by the application regarding their modification and any other operations that are available regarding this matter. Another thing would be that the software allows you to open .EPS files that were created with Adobe Illustrator and although the software supports this type of file it is known that if you are trying to open an .EPS file which was created with a version of Illustrator higher than 10.0 you will not be able to use the document or edit it in any way. This seems to be the cause to your problem and a quick resolution is to use a version of Illustrator prior to 10.0.
