Creating custom steel beam families and getting Revit to comprehend its shape

[trinity_metalworks]

I've been trying to create a family for a custom steel beam. I click: New family > Template Files > "Structural Framing - Beams and Braces" template, and then am met with a neat layout.  I edit the existing extrude's profile from the Left View, add Reference Planes that are parametrically equal in distance, add parameters for height, width, nominal wall thickness and constrain dimensions to those parameters... basically all the right steps to making a custom extrude. I change the material to Metal - Steel, the Section Shape's profile to one of the listed shapes (in this case, "C Profile"), save and then load into my open project.

So far, so good. It loads as a beam which I can lay out on or between columns, can adjust the dimensions in the Edit Type menu, and looks good... until I attempt a steel connection.

Revit doesn't seem to understand what this object is and only shows Generic Connection, and even then, that connection fails.

I'm sure I'm missing a step in creating a family, but can't for the life of me figure out what it is. I download other people's .rfa's and same problem. Can't find a tutorial on custom beams that isn't about concrete beams.

[trinity_metalworks]

One of the errors I get when making a connection reads, "Incomplete StructuralSection parameters". I'm sure the main problem is not enough parameters, but I don't know where to go to find out what the required parameters are in my case.

[jay_colcombe]

I think this is related to inadequate Section Properties which is common when creating your own Family and these are critical when building the Connection - I always tend to use a Prebuilt Family and edit for my needs as I know it works OOTB and should after my edits.

Steel Connection warning in Revit: "Incomplete Structural Section Parameters"

A Handy Tip For Section Shapes In Revit Structural Framing And Columns | GRAITEC