What version do I need for HD video?

I’m using iStop Motion v2.8.4. When I try to create a session with a size of 1280 x 720, I get a message saying “Width cannot be greater than 960,” but I know my webcam supports 720p video, so I’m assuming it must be the software. Can I get HD support if I upgrade to a more recent version? I looked through the iSM version history, and I couldn’t find anything that said “HD support started in this version.”

Could someone at least tell me if the version they’re using supports HD video?

I guess, you have an iStopMotion 2 Express license, that doesn’t support HD video. iStopMotion 3 does support any resolution there is.
iStopMotion 2 Pro supported HD video and above.