Bsod: unexpected_kernel_mode_trap

I’m a long time user of CryptoMator at home. A couple of days ago, I installed it on a newer computer. I created a vault on a network share. Just now, as I had an app I wrote reading TIFF files from the vault and saving images to it, while simultaneously trying to view the files in Windows Explorer, I got a blue screen of death (haven’t seen one of those in a LONG time).

The error displayed is UNEXPECTED_KERNEL_MODE_TRAP.

Running version 1.4.2 on Windows 10 Pro.
Network is wired, not wireless.


I have a similar problem with the same displayed Bluescreen error with Cryptomator V 1.4.3 and Dokany.

I have already mentioned it in this thread, but until now, nobody seems to care…

Interesting that you have the Problem with V 1.4.2, because since I switched back from V 1.4.3 to V 1.4.2, I do no longer experience Bluescreens.
Edit: Unfortunately, I now also experience this Bluescreen with V 1.4.2.

A bit more information on the Bluescreen:

Can you please try with V1.4.4?

1.4.4 only affects WebDAV. If there is a BSOD caused by the Dokan Driver, it will not be fixed by updating to 1.4.4. :cry:

I’ll try it, but I’m confused why there’s a 1.4.3 and a 1.4.4 version already available. I just downloaded and installed this a few days ago (2/7/2019). Have there been TWO new updates since then?

I’m also concerned this might be a Dokan issue. Anyway, I’m updating now.

Well crap! Bit9 on my work computer has blocked it, so now I sit and wait a day or two for them to white-list it.

Maybe it is a new windows update. Did Windows installed a new Update before the BSOD?
Regarding dokany, i couldn’t find any recent BSOD reports on their bug tracker

I do not see a link between Windows Updates and the occurance of the BSODs.

When I search my computer logs, I retrieve the following data:

  • 18.01.2019: 2019-01 Update für Windows 10 Version 1803 für x64-basierte Systeme (KB4023057)
  • 06.02.2019: Occurance of the first BOSD caused by Dokan driver (with Cryptomator V 1.4.2)
  • 12.02.2019: Update of Cryptomator from V 1.4.2. to 1.4.3
  • 13.02.2019: 3 BOSDs caused by Dokan driver
  • 14.02.2019: Return to Cryptomator V.1.4.2
  • 15.02.2019: 1 BOSD caused by Dokan driver. Afterwards switch to WebDAV and no BOSDs since then
  • 16.02.2019: 2019-2 Sicherheitsupdate für Adobe Flash Player für Windows 10 Version 1803 für x64-basierte Systeme (KB4487038)
  • 16.02.2019: 2019-2 Kumulatives Update für Windows 10 für x64-basierte Systeme (KB4487017)
  • 17.02.2019: 2019-2 Update für Windows 10 Version 1803 für x64-basierte Systeme (KB4023057)

Mhm, well then windows updates can be excluded i guess. Just thought that maybe a change in the windows system could cause the error in dokan.
What is your dokany version?

Oh, and i found the fault description:

From the trap code, i guess the error is more specifically a so called double fault. Later in the article a possible reason for this is given:

A double fault can occur when the kernel stack overflows. This overflow occurs if multiple drivers are attached to the same stack. For example, if two file system filter drivers are attached to the same stack and then the file system recurses back in, the stack overflows.

In this case it could be stacking of dokany with networkshare. But this is just a guess.

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The Windows Control Panel says I am using ‘Dokan Library (x64)’. It is the one which was installed together with Cryptomator V 1.4.2.

I have not changed any hardware of my computer which could lead to the installation of a new faulty driver.

And I rarely use network shares. I would not swear on it, but I do not think I had a network drive connected at the time of the BOSDs.

But I am using Cryptomator in conjunction with Google Drive Filestream which is integrated into Windows by means of a drive.

No Windows updates for quite a while. We’re still on Windows 10 Enterprise 1607 (I said “pro” before… It’s actually Enterprise).

I have the same version of Dokan library. However, I’ve updated from 1.4.2 of Cryptomator to 1.4.4 since I had the error. I don’t know what version of Dokan was installed before the update. I haven’t had a BSOD since the update, but I haven’t used it all that much yet either.

Since nothing seems to happen here anymore:

Are you going to fix this issue? Or do I have to accomodate with either constant BSODs under Dokany or switch to WebDAV?

Sure, if you can say where the problem is exactly and the problem can be fixed inside cryptomator.
But since i doubt both, there won’t be at least a quick fix.

As in the technical explanation given, it’s very likley that the directory of the vault is provided through several kernel drivers (for example over dokany over a network share over …) and this leads to the BSOD. I don’t know your set up, but maybe there are even some drivers stacked which you don’t know about.

If its a Dokan issue and if none of us is a developer for dokany, the only option is to fill in a bug report. But even this is unclear.

I guess your only option is currently WebDAV. If you can provide a minidump or dump anaylze output for the BSOD, we can report it to the dokany developers.