SafeGuard LAN Crypt Client - If SafeGuard LAN Crypt and specific VPN software (crypto.sys) are installed on the same computer a blue screen occurs

  • Article ID: 107119
  • Updated: 28 Sep 2010

If SafeGuard LAN Crypt and specific VPN software (crypto.sys) are installed on one machine a blue screen occurs.

The blue screen will show an error message that is similar to the following:

STOP: 0x00000050
on file crypto.sys

The computer may restart automatically.

SafeGuard LAN Crypt v.3.13 and above.

Important: SafeGuard LAN Crypt v.3.13 retires on September, 30th 2010. We recommend you update your version as soon as possible – for further information please contact your Sophos sales representative.

Client OS
Windows 7, Windows Vista, Windows XP

What to do

This behaviour was reported recently and could be reproduced by our Tecnical Support team. We are currently investigating this problem. This document will be updated when new information or a solution becomes available.

Our first investigations indicate that the blue screen is caused by the crypto.sys driver from the VPN Software.

The driver crypto.sys tries, when being loaded, to read the file "crypto.sys" (itself). The problem is that the read process is not stopped after everything was read. Although all the time an END_OF_FILE is returned, it keeps trying to read 0x800 bytes. This keeps on happening (thousands of times) until eventually the crash happens.

If you are experiencing this behaviour, we recommend to register a support request with your VPN Software vendor. To get more detailed information regarding this behaviour please contact our helpdesk and refer to this article (107119).

If you need more information or guidance, then please contact technical support.

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