Hi, @darcy.knopp;,
Object enabler works with AutoCAD when Advanced Steel is not installed to open Advanced Steel models.
If you have Advanced Steel and you want to Append your model in Navisworks, try to Explode all advanced steel objects first, then save your model as DWG and then append it in Navisworks.
Alternatively, you could export different file formats from Advance Steel (like IFC, etc.) and then append them in Navisworks.
If you don't have Advanced Steel, but you have installed Object Enabler, try to open your model with Autocad. I'm not sure if it will work, but try to explode Advance Steel objects then save and append this model in NW.