Why do Revit Models get corrupt while working over a VPN connection?

Issue:

• Revit Models becomes corrupt while working over a VPN connection.
• When you try to synchronize with the central model (Sync with Central), a message informs you that the "The requested operation cannot be completed because the model is not currently available," or the system crashes.
• Poor performance or crashes in a Revit file-based workshared project over a VPN
• When working in a file-based workshared project over a VPN, project members encounter:
  • Lagging.
  • Performance degradation.
  • Slow or failed syncs to central.
  • Issues opening files.
  • Model corruption.
  • Program freezing or crashing.
• Can Revit's file-based worksharing be used successfully on cloud storage solutions (e.g. Dropbox, Box, OneDrive, SharePoint, ShareFile, Google Drive, etc)?

Causes:

Bandwidth and latency issues on an Internet / VPN connection.

The requirement for File-based Worksharing is to have the local copy of the model and the central file at the same geographic location, within the same Local Area Network (LAN) (Within the office). When using file-based worksharing, the local file and the central file exchange data constantly even if there is no synch process running and this data traffic does not have the necessary protections to operate effectively over the variable bandwidth and latency that would be encountered on an Internet/WAN connection.

Solution:

To resolve this issue, limit the use of file-based worksharing to local area networks (LAN environment):

For best results, see the following references:

Note: The best option for working between office and Remote

Revit Cloud Worksharing (BIM 360 / BIM Collaborate) 

Connects project teams with centralized access to BIM project data in the cloud. For more information, Schedule a Demo of BIM 360. Follow this link to Get Started with BIM Collaborate and BIM Collaborate Pro.

Benefits:

• Allows multi-firm collaboration (including user level controls for project access).
• Includes access to BIM 360 Document Management service.
• Does not require purchase or maintenance of server hardware.
• Users are not tied to single system or location (access within Revit is tied to Autodesk Account sign-in).
• Project data is stored in the cloud.

Limitations/Costs:

• There is a recurring (Annual, Quarterly, or Monthly) cost for each user accessing the service.
• Revit LT is not supported in this environment.
• WAN performance will impact operations that require interaction with the server (opening the project, synchronize, reload latest).

• When connecting to a remote machine to overcome the issue, make sure that the remote machine is located within the same Local Area Network as the server drive storing the Revit central model you wish to collaborate with.

Note: Most cost-effective option for users working Remotely outside to office Local Area Network (LAN) at home.

Remote Desktop

With local systems already set up, you can use Remote Desktop from another location to access Revit and work on projects.

Benefits:

• Remote Desktop is included with Windows.
• Project Data remains on the local network.
• System performance is not limited by the remote system.

Limitations/Costs:

• It's necessary to maintain the local systems to remote into.
• Network performance will impact higher resolutions (for example, high resolutions require more data transfer).
• Usability will suffer over larger geographic distances.
  • The performance is based on individual internet connection at the office and at the physical remote location.
  • There is no way to manage consistent internet speeds and latency issues
  • The connection between the two location will only be as fast as it’s slowest component. 

Note: Most cost-effective option for users working BETWEEN OFFICE NOT a support solution for Remote users outside the office.

Revit Server

Revit Server facilitates collaboration between users in different offices across a WAN. For more information, see the About Revit Server. Follow this link to How to install and configure Revit Server.

Benefits:

• Included with a Revit license.
• Allows collaboration between different offices in a company.
• More users can work in a server-based model at the same time (compared to file-based worksharing).

Limitations/Costs:

• Only stores Revit RVT data. For other file types a separate WAN solution is required.
• Requires server hardware.
• Revit LT is not supported in this environment.
• Designed to work within a single domain (that is, not set up for multi-firm collaboration).
• Designed to work between offices (for example, home users may see reduced performance without a local accelerator).
• Bandwidth and Latency requirements (3Mbs and 100 ms) may be difficult to achieve between different continents.
• WAN performance will impact operations that require interaction with the server (opening the project, synchronize, reload latest).
• Revit LT is not supported with this environment.

Note: IT IS NOT SUPPORTED: Can Revit's file-based worksharing be used successfully on cloud storage solutions (e.g. Dropbox, Box, OneDrive, SharePoint, ShareFile, Google Drive, etc)?

Simple Answer

If an experience similar to using file-based worksharing in a LAN environment is expected, then the answer would be no.
 

More Complex Answer

File-based worksharing in Revit was designed before the proliferation of cloud services and storage. The protections put in place to ensure that only one user owns a particular element or workset does not take into account other applications/services interacting with the files, and replicating them.
 
As a result of this, problematic behavior that could be encountered when working in such an environment would include:

• Corruption of the central model.
• Lost work, if two people synchronize at the same time, one of the user's changes will be lost while the others are retained.
• Incompatible local models where data cannot be successfully synchronized back to the central model.

Reference:
Autodesk Knowledge Network:

Revit Cloud Worksharing

https://knowledge.autodesk.com/support/bim-360/learn-explore/caas/CloudHelp/cloudhelp/ENU/About-BIM360/files/about-bim-360-design/About-BIM360-about-bim-360-design-about-revit-cloud-worksharing-html-html.html