[quote user="Daniel Thornhill"]I was trying to import through Microstation using the Data Acquisition>Surfaces>Create Surface>Import External>Import Raster.
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The mention of "Data Aquisition" tools indicates that this is not a plain installation of MicroStation you are using. I believe you are working with one of Bentley's Civil Design software packages, possibly InRoads. Would you be able to advise which other Civil Design software you might have installed on top of MicroStation and the version. I can then allocate your post to the correct support forum.