Hi All, I was trying to build Documentation/DocBook, but build is failing with below error. what could be the reason for below error?. I am using Ubntu 14.04 LTS, and my kernel version is 4.5.0-rc7 dsp@BLR-PCUB-01141:/usr/src/linux-stable$ sudo make pdfdocs PDF Documentation/DocBook/device-drivers.pdf Using catalogs: /etc/sgml/catalog Using stylesheet: /usr/share/docbook-utils/docbook-utils.dsl#print Working on: /usr/src/linux-stable/Documentation/DocBook/device-drivers.xml openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:55538:7:E: document type does not allow element "sect1" here openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:56585:7:E: document type does not allow element "sect1" here openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:58367:7:E: document type does not allow element "sect1" here openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:58410:7:E: document type does not allow element "sect1" here openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:58834:4:E: non SGML character number 128 openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:58834:5:E: non SGML character number 157 openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:58834:14:E: non SGML character number 128 openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:58834:15:E: non SGML character number 157 openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:59406:7:E: document type does not allow element "sect1" here openjade:/usr/src/linux-stable/Documentation/DocBook/device-drivers.xml:59778:12:E: end tag for "sect1" which is not finished make[1]: *** [Documentation/DocBook/device-drivers.pdf] Error 8 make: *** [pdfdocs] Error 2 dsp@BLR-PCUB-01141:/usr/src/linux-stable$ Regards, Madhu