KVM mode displays black screen; keyboard works, mouse does not

from Stardock Forums

I have been using Multiplicity KVM without issue until recently.  Now when I connect using KVM mode, the KVM window is black, the primary machine's mouse does nothing on the secondary machine, but the primary machine's keyboard works to interact with the secondary machine (i.e., I can ALT-TAB between apps, CTRL-ALT-BACKSPACE brings up the CTRL-ALT-DEL screen, I can type in applications, etc).  Seamless mode works without issue between these two machines (note that I only enabled seamless mode when the KVM mode stopped working properly).  I have made no software or hardware changes to either machine between when it was working and now.  Primary is my personal machine; secondary is a work supplied machine to which I have no admin access.

I have already gone through the suggestions in https://forums.stardock.com/489366/page/1/#3717862, ensuring that all apps are forced to use my primary video card, an RTX 4070Ti, to no avail.

Primary Machine (Desktop)
Windows 10 22H2
Multiplicity 3.57 Build 00103.kvm.stm

Secondary Machine (Laptop)
Windows 11 23H2
Multiplicity 3.57 Build 00103

Again, this was working without issue until a few days ago, and no changes have been made on either machine between the time it was working and when it stopped working.

kvm black screen multiplicity
3,274 views 3 replies
Reply #1 from Stardock Forums Top

Hello,
I have forwarded your problem/question to Stardock Support Team for their assistance. Please keep an eye on this thread for any updates. We appreciate your feedback and patience.

Basj,
Stardock Community Assistant

Reply #2 from Stardock Forums Top

I have been using Multiplicity KVM without issue until recently. 
End of quote

Again, this was working without issue until a few days ago, and no changes have been made on either machine between the time it was working and when it stopped working.
End of quote

That would defy logic. Clearly, MP has not changed, thus, something else has: Windows itself, a setting on it, a 3rd party app, driver or policy on the work PC, etc.

Primary is my personal machine; secondary is a work supplied machine to which I have no admin access.
End of quote

That is going to make supporting this nearly impossible.  At the very least, we were going to have you uninstall \ reinstall MP on all PCs.  

You would have needed Admin access to install it so can we assume you can readily request it?

Sean Drohan
Stardock Product Lifecycle Manager

Multiplicity - Control multiple PCs using one keyboard and mouse
Reply #3 from Stardock Forums Top

Quoting sdrohan, reply 2

That would defy logic. Clearly, MP has not changed, thus, something else has: Windows itself, a setting on it, a 3rd party app, driver or policy on the work PC, etc.
End of sdrohan's quote

It's possible, even likely, that any number of updates were installed on the secondary machine in the background.  Unfortunately, due to the restrictions in place on the secondary machine, I don't have any reliable way to determine what updates may have been installed.

Quoting sdrohan, reply 2

You would have needed Admin access to install it so can we assume you can readily request it?
End of sdrohan's quote

I was able to get approval for the use of MP, but it was installed remotely by the systems admin rather than me being given even temporary admin access to the local machine.  In short, I might be able to get the admin to remove and reinstall MP, but I don't know how likely that will be.

One thing I have noticed in the past couple of days, which may point to this being somehow network related, is that in seamless mode sometimes my mouse cursor "wanders" significantly when working on the secondary machine.  Even if I remove my hand from the mouse, the cursor moves slowly around on the screen for a few seconds.  I couldn't say entirely how long this may have been occurring, as I only recently started using seamless mode between these specific machines and it's not something that happens frequently.

I fully understand that my inability to get admin access on the secondary machine may leave me out of luck in troubleshooting this issue, so not to worry if the answer is "Sorry, can't help". :)

Even with the mouse movement issue described above, seamless mode works well enough that I have no reason to stop using MP entirely; just would be nice if I could somehow get KVM back up and running.