What is the cache.ucf?
This file's default location is here: C:\Users\<user.name>\AppData\Local\Bentley\OpenRoadsDesigner\10.0.0\prefs. It contains the most recently opened configuration location, workspace name and workset name. ORD needs these names to load the workspace/workset. The variable _USTN_CACHECFG is predefined and points to this file. The most recent workspace/workset name used to be contained within the Personal.ucf, but has been moved to the Cache.ucf.
The msconfig.cfg located here: C:\Program Files\Bentley\OpenRoads Designer CE 10.11\OpenRoadsDesigner\config loads and reads the cache.ucf. This file is read after the WorkSpaceSetup.cfg and before the WorkSpace.cfg.