Tip submitted by Stan S. in San Francisco
If you are a regular user of Navisworks to perform 3D coordination or 4D simulations using model data from Revit, you may have encountered a problem with updating the NWC files exported from Revit. Navisworks can directly open or append models from a number of formats including DWG, DGN, IFC, and so on. It does so by creating temporary files called cache files (NWC). Because Navisworks cannot directly open a Revit project file (RVT), Autodesk provides a free exporting tool to create NWC files directly from a Revit model; however, if you have a Navisworks file set (NWF) open when you try to export from Revit, you will see this error:
To solve this, go to the Navisworks Options Editor (under the Application button) and examine the Model options. You may have to scroll down to find this option, but make sure the setting for “Close NWC/NWD Files On Load” is checked as shown below. This will allow you to overwrite the NWC files while Navisworks is running.
With this setting enabled, you must remember to refresh your file set when an NWC file is overwritten. Found on the Home tab (or by pressing F5), this is the usual method for updating when an original model of another format (DWG, DGN, IFC…) is received.