In some cases, 
  Revit cannot open, save, or synchronize with files. 
 
  Issue: Some antivirus software solutions lock files, preventing other applications from accessing them. 
 
  Solution: You or your network administrator can define the following file extensions as exceptions in your antivirus filter. 
- Revit Projects (RVT) 
  
 
- Revit Families (RFA) 
  
 
- Revit Templates (RTE) 
  
 
- Industry Foundation Classes (IFC) 
  
 
- AutoCAD drawings (DWG) 
  
 
- CAD Data Transfer (DXF) 
  
 
- MicroStation drawings (DGN) 
  
 
- ACIS models (SAT) 
  
 
- Trimble® SketchUp® drawings (SKP) 
  
 
- Images (BMP, JPG, and PNG) 
  
 
- Data (RWS and DAT) 
  
 
Note: It may be necessary to contact your network administrator to add these exceptions.