I've been trying to setup a forge server for awhile and I'm stuck at the part where I have to open the forge.jar file that should create new folders but instead gives me this error. https://imgur.com/a/XdNZWDM

Thank you for your very quick response but I found the issue and it does not seem that not having Java 8 was the issue. I went to add or remove programs in setting and found out I had like 3 different versions of java including 8. I removed all of them and reinstalled 8 and the jar file created the necessary folders. Again thank you.