Windows 11 crashes. "What failed: prl_virt_disk_balloon.sys"

My hardware and software:
MacBook Pro 2023, M2 Pro, 16 GB of RAM.
MacOS Sequoia 15.6.1
Parallels Desktop for Mac Version 26.0.1 (57243)
Windows 11 Pro version 24H2, OS Build 26100.5074 (Installed on Sept 3rd, 2025)

Windows crashes with the message:
Stop code: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (Ox7E)
What failed: prl_virt_disk_balloon.sys

I reinstalled Windows 11 from scratch and this failure is still here. I didn't have this problem with the previous Parallels Desktop version. I don't think I will renew my subscription because of this problem and will try VmWare or UTM, unless the people at Parallel's customer support solves this.

 

Hello Support-
I am having the same issue (Stop code: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (Ox7E), What failed: prl_virt_disk_balloon.sys)
with Windows 11 and Windows 2025 VMs with Parallels Desktop 26 for Mac Version 26.0.1 (57243). VMs crash randomly after ~ 5 minutes of use.
Any estimates on fix?
Thanks,
Mark

 

I have exactly the same problem. Could anyone post the solution here?

 

Good evening.
I have the same error:
Stop code: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (Ox7E)
What failed: prl_virt_disk_balloon.sys

System: Windows 11

Current Parallels version: Version 26.0.1 (57243)

Windows 11 constantly reboots and it is impossible to work.

The error started appearing after updating to a new version of Parallels a few days ago.

What could be the problem?

 

I also have been having the same issue for a while. Repeated crashes. My Windows, Parallels Desktop, and Parallels Toolbox for Windows are all updated. It is becoming rather annoying and unproductive. Can you please share the solution or open a ticket for me?

 

I still have this problem. Please is there a solution or update for this problem?

 

is there a solution Brian?

 

The same with Windows Server 2015 arm64: installing latest Tools, nothing but crashing!
Minidumps always point to ...baloon... crash.
Very annoying! (latest version 26.x)

 

Update: I suspected there might be an issue in the ballooning of the virtual hard disk (from the name of the driver that crashes). I disabled "sync free space with Mac" in the Hard Disk configuration for the VM and I haven't had a crash in several hours.

I will post back after a few days to see if it has happened again with the same error.

 

a piece of the debug log (minidump using WinDbg.
Installing the tools from 26.x started the crashes

.......
FAULTING_THREAD: ffffc884be852080

EXCEPTION_RECORD: ffffaa8ecba98f08 -- (.exr 0xffffaa8ecba98f08)
ExceptionAddress: fffff80178081254 (prl_virt_disk_balloon+0x0000000000001254)
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
Parameter[0]: 0000000000000000
Parameter[1]: 000001f3f7a02ebc
Attempt to read from address 000001f3f7a02ebc
......

 

Windows 11 Keeps restarting for the past couple of days. Applied updates to Windows 11 and Parallels Pro leading up to this issue (both now have latest updates). MacBook Pro M4 Max with macOS Sequoia 15.6 (not the latest 15.6.1).

 

I am the original poster of this thread.
Well, I have been told that I need to uninstall Norton Antivirus from Windows 11. I did it, and now it seems that I am not getting more crashes. But it is very important for me to run Norton, for obvious reasons. It was not a problem to have Norton running before I upgraded Parallels to Version 26. My logic tells me that Parallels has a bug in its new version of the software and they need to fix it instead of trying to avoid the problem by asking me to uninstall Norton.