Windows 11 Update (Jan 2026) breaking Sandboxie + Steam

J

Jose

New member
After the latest Windows 11 update installed yesterday (Patch Tuesday January 2026), Sandboxie has become unstable with Steam and Chromium-based components.

Both Sandboxie Classic 5.71.9 and Sandboxie Plus 1.16.9 show the same behavior:
  • Steam starts inside sandbox but gets stuck on infinite loading
  • steamwebhelper.exe processes spawn but UI never finishes loading
  • No crash or explicit error, just frozen or endless “connecting” state
  • Issue appears even on freshly created sandboxes with default settings
  • Worked correctly before the Windows update
System details:
  • Windows 11 Pro
  • Virtualization enabled
  • No BIOS changes
  • Issue started immediately after Windows Update installation
Tried so far:
  • Clean reinstall of Sandboxie Classic and Plus
  • Fresh sandbox profiles
  • Updating compatibility templates
  • Enabling Edge/Chromium compatibility workaround
  • No improvement
This strongly suggests a kernel/security layer change introduced by the latest Windows cumulative update, affecting process hooking / sandbox injection used by Sandboxie and Chromium-based apps such as SteamWebHelper.

If anyone has found a confirmed workaround (specific template settings, driver parameters, or Windows security components that interfere), please share.

Also would be helpful to know if this is already tracked as a known compatibility issue with the January 2026 Windows updates.
 
Hello, thank you for the details.

This issue might be the same as reported on GitHub.

This also might be due to Chromium based browsers, doing something different from before, what Sandboxie did not yet adapt to.
 
Jose said:
So I understand that the solution is to wait for a Sandboxie update.
Click to expand...

Yes, unless someone finds a workaround that can be applied by users, I think only a change in how Sandboxie operates will resolve this via an update.
 
I have also had the same issue. Can confirm both classic and plus are affected. - Saw this posted on the github forums as well, like mentioned above. And I posted it there first, because registration here was broken for a bit.


Image

Its one of these 2 updates that caused the issue. I was able to narrow it down to that at least. - No issues up untill this installed. And the issue occured immediately after I rebooted/installed these windows updates. Most of my gaming community is holding off on the windows updates right now to avoid repeating this block. As we all run multiple instances of steam for the game we all play.

I've tried every workaround I could find. From allowing full access in the sandbox to installing steam directly to the sandbox. - My absolute last choice is to do a virtual machine - but thats such a pain to setup. This is way simpler. Hopefully Xanasoft will patch it.
 
Thank you for checking the latest version and reporting back. It could have been that it was fixed as a side effect, since the root cause was not targeted. It's bad that this is not yet resolved.
 
Screenshot 2026-02-24 172219.png

This Windows update today fixed the originally sandboxie issue for me.

I no longer have to do the workaround that has been mentioned on the github of killing SandboxieRpcSc.exe over and over till it loads steam. - (Which does work. For those of you not keeping up with the convo there. There has been a lot more help than this forum - over there on github.)

I tested sanboxie with multiple boxes and a instance of steam running in each one. No issues for startup, account selector, anything. Everything is working as it was prior to the start of this post.
 
Last edited:

February 24, 2026—KB5077241 (OS Builds 26200.7922 and 26100.7922)​

I loaded this update and I am still unable to load Naval Action on Steam. Are you loading another Steam game?
 
brighteye23s said:

February 24, 2026—KB5077241 (OS Builds 26200.7922 and 26100.7922)​

I loaded this update and I am still unable to load Naval Action on Steam. Are you loading another Steam game?
Click to expand...
Yeah, im not sure about specific game issues.

My issue was along with the OP's - Sandboxie wouldn't succesfully load additional instances of steam at all. - Wasn't specific to any game.
 
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