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[OBSOLETE] Unofficial workaround for Snapman.sys BSOD Windows safe mode

Thread needs solution

ATIH 2016 b5518

Hello everyone,

I spend some brain into the BSOD problem with snapman.sys that prevented to start Windows in safe mode.

references:
https://forum.acronis.com/de/node/96768
https://forum.acronis.com/de/node/96465

I want to share an unofficial solution.
Please be aware that this solution is not yet proven / supported by Acronis.

Affected product:
Acronis True Image Home 2016 build 5518

Tested with:
Windows 10 pro 64bit (release build 10240)

Not tested but expected to be compatible:
all Windows versions

Problem:
BSOD
System_Thread_Exception_Not_Handled when trying to start Windows in Safe Mode.
Caused by snapman.sys

Workaround:
Altering registry entry ImagePath under [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\snapman]

Altering registy key DWORD "Start" to value 4 (HEX)

As pointed out in one of the threads I have noticed that the path to the snapman.sys is missing the %systemroot% variable. This is commonly present in other driver entries that will be loaded by the Windows Kernel at boot time, however I've also noticed that it is not included in all of those drivers located in the Windows registry.

What I can say now is that adding the %systemroot% to the ImagePath string does fix the issue.
The BSOD in safe mode came up reproducibly as soon I reverted that string to the Acronis default without the %systemroot% variable. (original entry is: system32\drivers\snapman.sys)

Based on my knowledge about Windows, this solution should also work for other 64bit versions of Windows, so Windows 7 and 8.x but I have not tested this.
Furthermore I haven't tested the behaviour for any 32bit version of Windows and advise not to use the workaround on a 32bit Windows installation. Don't apply the hotfix if you are not sure what you're doing and don't apply it on Windows versions at all that haven't been tested.

Attachment Size
hotfix2.png 58.76 KB
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oh the backlash came fast. Editing the registry according to the previously posted workaround makes it possible to start Windows in safe mode, but renders the mounting of TIB files inoperable.
So you could use this workaround to start Windows in safe mode but have to revert it and restart your computer if you need the feature to mount TIB files via the explorer.
Apparently the previous hotfix does not fix the issue but prevents the driver to load at all :(

If I would have wished that to happen it would have been an easier solution set the start DWORD value to 4
I've included this workaround now in the original post

https://support.microsoft.com/de-de/kb/103000

I am sorry this workaround does not completely solve the issue. Btw, I really needed to start Windows in safe mode to use DDU to get rid of my Nvidia driver problems, that's why I eagerly searched for a solution.

issue fixed in in build 5576, as far I have monitored the registry key the update to the mentioned build will revert all changes to default,
so basically the Imagepath and Start DWORD is set as nothing was ever changed.

Please check if you still have the BSOD when starting in safe mode after the upgrade. I cannot reproduce it anymore.

hi Karl:

I now have the same problem (BSOD in safe mode or normal mode caused by snapman.sys) . But I wonder how to modify the registy key because I can not enter the OS normally.

thank you!

You can remove the snapman service using WinPE recovery media. See the attached file for detailed instructions.

Attachment Size
406647-137218.docx 13.33 KB

You're welcome. Let us know if you get your system back.

Hi Mustang:

thanks

I tried to follow the steps to repair my system. But I can not find the "snapman" in

UpperFilters of HKEY_LOCAL_MACHINE\REMOTE_STSTEM\ControlSet001\Control\Class\{4d36e967-e325-11ce-bfc1-08002be10318 

HKEY_LOCAL_MACHINE\REMOTE_STSTEM\ControlSet001\Control\Class\{71a27cdd-812a-11d0-bec7-08002be2092f.

Are the two steps necessary for repairing? Can I skip the two steps ?

 

You only need to remove the snapman UpperFilter if it is present. You should only need to delete the snapnam servive to make the system bootable.

hi Mustang:

I want to give you a big hug. My system is back. thank you !!!!!!!! 

^_____________^

Great to hear.