In some cases, connecting to a data source with the FDO ArcGIS provider can cause the AutoCAD materials library downloader to go into a loop. If you notice slowdown on your system after connecting to an ArcGIS source, use this workaround to disable the materials library downloader.
Locate AdDownloaderCore.dll in the Map3D install directory, e.g. C:\Program Files\Autodesk\AutoCAD Map 3D 2012\AdDownloaderCore.dll . Rename AdDownloaderCore.dll to something like X_AdDownloaderCore.dll. This disables the downloader.
Run Map3D again
My question: Inanyfileis AutoCAD materials library loaded? and is it in C:\Users\xxxxx\AppData\Local\Temp?
is it (Library--xxxxxxxx.LayerDefinitionLayer17.gws)