Converting an imported body to sheetmetal?

I am a long time SW user but new to sheetmetal. I am having to bring in a bunch of legacy files and try to get everything up to date in SW. I keep running into issues with a few thing and was wondering if it is a setting issue or something else that im not aware of.

On the attached part, when trying to convert to sheetmetal I pick the main flat and then hit the "collect all bends" tab. At that point I keep getting the "unable to thicken surface" error.

Is it something that im doing? Is there a way around this?

Thanks for any help you can provide.

SolidworksSheet Metal