The error appears when a Kerberos ticket has expired. This might lead to failure in accessing certain resources that the user/service might need. If a client presents an expired session ticket when requesting a connection to a server, the server returns an error message. The client must request a new session ticket from the Kerberos Key Distribution Center (KDC). Once a connection is authenticated, however, it no longer matters whether the session ticket remains valid. Session tickets are used only to authenticate new connections with servers. Ongoing operations are not interrupted if the session ticket used to authenticate the connection expires during the connection.
In order for Kerberos to function normally, make sure that the time in the domain is synchronized. Unsynchronized time throughout the domain can lead to many Kerberos related errors.
Typically, this error occurs when the value for the "Maximum lifetime for user ticket Kerberos policy" setting is set too low.
See the following articles for information on Kerberos and on the "Maximum lifetime for user ticket Kerberos policy" setting: “Troubleshooting Kerberos Errors”, “Maximum lifetime for service ticket”, “Authentication errors caused by unsynchronized clocks”, and “Kerberos authentication tools and settings”.
As per Microsoft, this is because an unknown device was specified and their suggestion is to retry the command, using a correct device name. While this may be a good suggestions for programmers developing applications that connect to various device drivers, it will not help the user of the application that has no control over what device the application calls.
In reality, there could be many things wrong with that device:
- the device is not installed on that system (and there are no drivers for it).
- the device driver is not compatible with the Windows OS where is installed (for an example see M157678). Typically, the solution here would be to obtain the latest driver from the the device manufacturer or install the latest service pack (as in M149694) but sometimes (as in M157678), you may have to obtain an older version.
- the device may require certain hardware settings in order to work properly (see M167212)
- the hardware may be malfunctioning - if a plug-and-play device does not work properly it may fail to initialize and the software that is trying to use it may have problems contacting the device driver for it. One newsgroup post mentioned that this error was reported by a backup software after the tape library failed to start properly. They "fixed" the problem by recycling the power on that tape unit.
One important challenge in troubleshooting this type of problem is the ability to discover what is the device that cannot be found. My recommendation here is to try to understand what kind of hardware would that software use. For a backup packages for example is not that hard: a tape driver or a tape controller. Some other software packages may not be that easy.
Symbolic name: ERROR_BAD_UNIT
Build a great reporting interface using Splunk, one of the leaders in the Security Information and Event Management (SIEM) field, linking the collected Windows events to www.eventid.net.
Obtain enhanced visibility into Cisco ASA firewall logs using the free Firegen for Cisco ASA Splunk App. Take advantage of dashboards built to optimize the threat analysis process.