Subdomains or Subsites not working

Has anyone had success getting a subfolder website to run under their mydomain site from a link? My subfolder website runs OK stand-alone.

I tried installing nopCommerce and using tech support but they locked my ticket out saying they don't support 3rd party apps. Nop has a video showing theirs run on a host.

I bought the add-on for subdomains but sure see alot of threads of grief using that option.

I installed the mojoportal under my website from the Discount Web Gallery. It installed and then didn't run. The wiki didn't either. My website didn't work after installing the mojo in a subfolder. Followed the Discount instructions to a "tee".

Anyone got any of this working??