Running v5.31 I am getting an error when trying to export using Machine Job Site Design Exporter. 
Seems to be an issue with exporting surface, since I can export linework only using Machine Site Map exporter. I tried importing .dxf and .ttm into clean TBC file and get same error. I am using v5.31 and when I sent same .dxf and .ttm to co-worker also running v5.31 they were able to export .svl and .svd OK?
Please note that I am getting same error when trying to create .svd using Construction Data.