Warped geometry or problems with missing glazing are issues that can occur when importing gbXML files from Revit in particular. If you experience such issues (Please refer to images below for examples), it is recommended to go back to your Revit model, set the true north rotation and coordinates back to zero and export again. This will significantly improve the export.
Images from the Virtual Environment: Plan view of warped geometry (left) & issue resolved (right)
Images from Autodesk Revit: Specify Shared Coordinates
