It's a wired connection, and I get the error and disconnect while I am actively typing through the primary keyboard onto an app on the secondary computer.  There's definitely NOT a 6-second lack of reply... well, there might be a lack of reply from secondary to primary, but the primary to secondary information flow is happening when I get the disconnect.

With a wired connection, I'm not sure what 24H2 would do to make the ethernet connection unreliable.

I've just bought Multiplicity v4 pro and I'm getting this issue. I managed to get my desktop connected to my laptop (using WIFI) and everything worked well for an hour or so. But now I'm getting alternating messages on primary: complaining about a "wrong passcode" first, and then the "secondary did not respond in time".

Follow up: restarting the secondary fixed the issue, but it started to happen again (almost) exactly an hour later.

Did you try "Flush DNS Cache"? 

I'm using currently Muliplicity 3 KVM Pro with 9 Secundaries, 7 of them on Win 11 24H2, 2 on Windows 10. The Primary running on Win 11 24H2. And I have any issues.

If you are connecting via hostname, try entering the IPv4 address instead. Example

You are also going to want to ensure you are using 4.0.0.4 on BOTH the Primary and all Secondary PCs.

The best tests are done if all PCs are wired. 

If all else fails, burn and reinstall on ALL MP PCs

https://support.stardock.com/space/SHC/1347158073/Multiplicity+purging+and+re-installing

Sean Drohan
Stardock Product Lifecycle Manager

Then you (each) would have something to try.

Sean Drohan
Stardock Product Lifecycle Manager

Could it be a firewall or anti-virus issue that is blocking the connection?

No VPN, I have Webroot installed on both PCs for years, so I doubt that's an issue.  Dell Command Update is wanting to do a BIOS update and a couple of other drivers.  I'll install those and see what happens, then try MP4 on both.

So, on the first day of using Multiplicity 4 Pro I encountered the loop twice. I executed "Flush DNS Cache" and it went away; however, I've been encountering connection problems since:

• On day two, my machines connected immediately but the cursor was a bit laggy.
• On days three and four (today) the cursor has been stable, but I've really struggled to make the initial connection after reboot of the two machines. On day three it took around ten minutes, and today I've been unable to make a connection.

The weird thing is, dispite all the problems, when I test the connection in the secondary configuration dialog it always returns success even when they won't connect.

@Mad Trix - Thanks for the flush DNS cache tip; however, I think this problem is related to version 4 and/or connections between Win 11 24H2 and 23H3, and not Win 10. I don't think your setup rules anything out here.

I've been able to get connections working reliably now. Every morning, I drag the secondary off the grid, wait 5 seconds, and then drag it back on. It connects almost immediately.