Cannot Synchronize to Central – System Volumes are Calculating

March 19, 2024 Jeremy Smith

Revit version(s):  Applies to all versions


Users working in Revit receive an error when attempting to synchronize their model with the central model that reads “Cannot synchronize with central because System Volumes are calculating.”  The full error message is pictured below.


The “Calculations” parameter for one or more duct or pipe system types is set to “All” or "Flow", causing Revit to perform calculations in the background.  The process may take a long time depending on the size of the system, and a user cannot synch until the process is completed.


1. To determine which system(s) are being calculated in the background, click on “Background Processes” in the status bar at the bottom right of the Revit window (or hit F11 key).


2. In the Project Browser, scroll down to Families > Duct (or Pipe) Systems > Right-Click on the related system that is calculating and select Type Properties…

3. Set the Calculations parameter to Performance and select OK

4. If the above action does not stop the background processes from running, you can force the processes to stop.  To do so, open Windows Task Manager

5. Go to the Details tab

6. Select the RevitWorker.exe process and select End task

7. Return to Revit and attempt to sync to central

Note:    You can also set Calculations to "None" to minimize background processes from running.  However, setting this parameter to "Performance" will turn off more calculations than if set to "None".    See:

About the Author

Jeremy Smith

Sr. Technical Support Specialist, AEC<br><br>Jeremy has been delivering service and technical support to customers in the AEC industry for over 25 years. He gained much of his AutoCAD/Revit experience serving as CAD Manager at multiple MEP/FP engineering firms in the Greater Boston Area. He then worked at Autodesk as a Technical Support Specialist, eventually becoming a manager overseeing the Revit and Vault support teams. Jeremy is excited to be in his current role as Sr. Technical Support Specialist at IMAGINiT, as it allows him the opportunity to work directly with customers every day and help them successfully leverage Autodesk’s solutions to achieve their business goals.

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