Unable to create solids issues...

please see attached video and dgn file. 

This is a very common and frustrating occurrence with connect. On this occasion the error states ''the Feature #2 cannot be created as it produces geometry that exceeds the solids area. Check the 'Solids area' setting in the working units section of the design file settings'

Firstly, there is no thicken #1 this is a surface with 0 thickness. 

secondly, the solids are is 4.2km. this object is around 3.2m long and I am trying to thicken by 50mm so definitely not outwith 4.2km

normal work around is to 'convert to smart solid' and retry however in this instance it makes no difference. 

When using legacy solids tools, I am able to extrude along path, so far as the preview shows, but the solid does not complete. 

Thicken Test.dgn