It's been a few days now that I'm trying to solve this problem and since I didn't figured it out yet I desperately need help. The file was originally in .stl format and I was able to create a surface on solidworks with it. Now I'm stuck with this very complex surface that I need to make a solid with. I tried the thicken feature but it doesn't work. I'll attach the file like that you guys can give it a try. I need to keep all the definition of the surface so smoothing out areas isn't really an option.
Thank you for your time.