Sadly, in such cases, we can only provide random troubleshooting steps based on previous (solved!) cases:
Check out the one with the lock icon in the Render Setup window. It really solves the issues sometimes. I also recall a similar case where it helped.
Please try the following points, which are based on our past user reports. In most cases, they are the easiest way to get the issue resolved.
-Disable any antivirus software you are using on all PCs (including Windows Defender and Firewall) - this is just to check if the issue is related to this software. You can then turn it back on.
-Open your scene, go to Render Setup, deselect the small "lock" icon in the top right corner. Click on any viewport, then click on the viewport you want to render again. Enable the "lock" icon in the top right corner of the Render Setup window again. Resave your scene. Unlocking and locking viewport like this sometimes helps with DR issues.
-Refresh the 3ds Max ENU folder by either renaming or removing it. Note that this will remove all your custom ui settings, keyboard shortcuts, etc, so it is best to leave a backup of the ENU folder.
See:
https://knowledge.autodesk.com/support/3ds-max/learn-explore/caas/sfdcarticles/sfdcarticles/Resetting-3ds-Max-3ds-Max-Design.html If the above 3 points did not help, here are some other ones worth trying:
-Add custom inbound/outbound rules in Windows Firewall.
See: Creating custom inbound and outbound rules for the DR Server application -
https://coronarenderer.freshdesk.com/support/solutions/articles/12000050816- Are you using some VPN software? If so, please stop using it and make sure you are using BB/DR on a "classic" local network.
- Do not mix Corona's DR and Backburner. Use only one or the other.
- Make sure on each computer there is only one instance of: 3ds Max, DR server, Backburner. If there are multiple instances running at the same time (for example two 3dsmax.exe processes), some issues may appear.
- Do not render from perspective view - use some kind of camera, preferably Corona Camera.
- Disable IPv6.
See:
https://medium.com/@JockDaRock/disabling-ipv6-on-network-adapter-windows-10-5fad010bca75- Go to Windows Services list and make sure "Function Discovery Provider Host" and "Function Discovery Resource Publication" are started. Set them to automatic start.
- Make sure you have network discovery enabled.
See:
https://www.isunshare.com/windows-10/turn-on-or-off-network-discovery-in-windows-10.html