Import/Export MicroStrategy Semantic Layer

I'm trying to import the semantic layer for a project that I have in MicroStrategy and although I have access to MSTR Intelligence Server from my desktop, my project source is not recognized by ER Studio Bridge.  I'm using tier 3 connection to the Intelligence Server (which is the recommended approach from MicroStrategy), does anyone know if this type of connection is supported?   Or is the 'Direct' tier 2 approach the only one supported?