While in a Terminal doing an update I get a few error messages. Please help E: Failed to fetch cdrom://Ubuntu 14.10 _Utopic Unicorn_ - Release amd64 (20141022.1)/dists/utopic/main/binary-amd64/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Failed to download repository information due to missing CDROM When updating I got this error message:  W:Failed to fetch cdrom://Ubuntu 11.10 _Oneiric Ocelot_ - Release amd64 (20111012)/dists/oneiric/main/binary-i386/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs W:Failed to fetch http://ppa.launchpad.net/synce/ubuntu/dists/your_ubuntu_version/main/source/Sources  404  Not Found   What to do?
Makeindex error when ! used in \index in align environment See MWE below. The symbol ! in the \index causes an error. This is only the case in align environments (not in equation). So it seems to have to do something with amsmath. If ! is put in an \mbox there is no error. But then of course the font size is not adjusted to subindices. Curiously enough, \index{$C_{K!!}$} (two exclamation marks) doesn't cause any error.    \documentclass{article} \usepackage{amsmath} \usepackage{imakeidx} \makeindex \begin{document} \begin{align} y\index{$C_{K!}$} \end{align} \printindex \end{document}     Any solutions suggested? I tried to find a topic here on this (possible problem) but I didn't.   I reported it at  but Tim Hoffmann pointed me that it is not a problem of editor. After tested with nano and pdflatex I'm posting here.  The minimal code produces errors. OK, we can solve it using \\{}.   But is this a problem with TeXlive 2014 or there are some good reasons to have that behavior.  \documentclass{report} \begin{document} test\\ [foo]  test\linebreak [foo]  test\newline [foo] \end{document}      ! Missing number, treated as zero.                        f l.3 test\ [foo] Is it possible for a physical object to have an irrational length? Are counters (noun) physical things? I want to upgrade my Ubuntu 13.04 to Ubuntu 13.10. I'm unable to do via GUI.   [ The reason why I'm unable to do so:  Via software updater, I proceed ahead and click upgrade (for upgrading my OS). I authenticate by providing my password. Then it proceeds and downloads upgrade tool. That time only (while downloading the tool) error message comes "system program problem detected". It then doesn't proceed ahead and I click to report the problem ]  So, I tried via command line but here also I couldn't succeed upgrading my OS.  For the same I ran   $ sudo apt-get update   Then I ran  $ sudo apt-get dist-upgrade   And then:  ravbholua@ravbholua-Aspire-5315:~$ sudo do-release-upgrade Checking for a new Ubuntu release Get:1 Upgrade tool signature [198 B]                                                                                                  Get:2 Upgrade tool [1,135 kB]                                                                                                         Fetched 1,135 kB in 6s (32.9 kB/s)                                                                                                    authenticate 'saucy.tar.gz' against 'saucy.tar.gz.gpg'  gpg exited 2 Debug information:    gpg: Signature made Friday 01 November 2013 10:34:27 AM IST using DSA key ID 437D05B5 gpg: Can't check signature: public key not found  Authentication failed Authenticating the upgrade failed. There may be a problem with the network or with the server.  ravbholua@ravbholua-Aspire-5315:~$    Please suggest how to go ahead and upgrade my OS. Cross-referencing between different files There is some conflict or error I don't understand. I can skip it and nothing visible happens. The output is okay and everything seems to be fine. Still I would like to get rid of the error message. If I run the following minimal example:   \documentclass[]{scrbook}  \usepackage[applemac, grafiken]{tahbiblatex} \usepackage[ngerman]{babel}   \begin{document}  Testing äüöaüä.  \end{document}   I get the error message:      ! Missing = inserted for \ifnum. &lt;to be read again&gt;                     , l.4 \usepackage                [ngerman]{babel} ?  ! Missing number, treated as zero. &lt;to be read again&gt;                     , l.4 \usepackage                [ngerman]{babel}   Here is my .sty file:  \NeedsTeXFormat{LaTeX2e}\relax \ProvidesPackage{tahbiblatex}[2012, by tah modified by sm]  \RequirePackage{ifthen}  \DeclareOption{latin1}{\PassOptionsToPackage{\CurrentOption}{inputenc}} \DeclareOption{applemac}{\PassOptionsToPackage{\CurrentOption}{inputenc}} \DeclareOption{cp850}{\PassOptionsToPackage{\CurrentOption}{inputenc}} \DeclareOption{utf8}{\PassOptionsToPackage{\CurrentOption}{inputenc}}  \DeclareOption{dvi}{% \newif\ifpdf \ifx\pdfoutput\undefined     \pdffalse \else     \pdfoutput=0     \pdftrue \fi}  \newcounter{Grafiken}\setcounter{Grafiken}{0} \DeclareOption{grafiken}{\setcounter{Grafiken}{1}}  \newcounter{Randausgleich}\setcounter{Randausgleich}{0} \DeclareOption{randausgleich}{\setcounter{Randausgleich}{1}}  \newcounter{Tabellen}\setcounter{Tabellen}{0} \DeclareOption{tabellen}{\setcounter{Tabellen}{1}}  \newcounter{Sync}\setcounter{Sync}{0} \DeclareOption{sync}{\setcounter{Sync}{1}}  \ProcessOptions  \RequirePackage{fixltx2e} \RequirePackage{inputenc} \RequirePackage[T1]{fontenc} \RequirePackage[T1]{url} \RequirePackage{setspace} %\RequirePackage[german]{varioref} \RequirePackage{textcomp}  \newcommand{\urlangabe}[2]{% $\langle$\url{#1}$\rangle$ -- Zugriff am #2}  \def\hierlockern {\begingroup \def\par{\endgraf\endgroup}%   \tolerance 1414%   \hbadness 1414%   \emergencystretch 1.5em%   \hfuzz 0.3pt%   \vfuzz \hfuzz%   \raggedbottom% }  \newcommand{\alleslockern}{%   \tolerance 1414%   \hbadness 1414%   \emergencystretch 1.5em%   \hfuzz 0.3pt%   \vfuzz \hfuzz%   \raggedbottom% } \ifthenelse{\value{Grafiken}=1}   {   \ifx\pdfoutput\undefined \newcount\pdfoutput \fi   \ifcase\pdfoutput       \RequirePackage[dvips]{graphicx}       \DeclareGraphicsExtensions{.eps}       \typeout{Paket tah Meldung: Die Option `grafiken' fuer DVI wurde gewaehlt.}% \else     \RequirePackage[pdftex]{graphicx}     \DeclareGraphicsExtensions{.jpg,.tif,.png,.pdf}     \typeout{Paket tah Meldung: Die Option `grafiken' fuer PDF wurde gewaehlt.}%   \fi}   {}  \ifthenelse{\value{Sync}=1}   {     \ifx\pdfoutput\undefined \newcount\pdfoutput \fi     \ifcase\pdfoutput     \RequirePackage{srcltx}     \typeout{Paket tah Meldung: Die Option `sync' fuer DVI wurde gewaehlt.}%     \else     \RequirePackage{pdfsync}     \typeout{Paket tah Meldung: Die Option `sync' fuer PDF wurde gewaehlt.}%     \fi }   {}   \ifthenelse{\value{Randausgleich}=1}   {\typeout{Paket tah Meldung: Die Option `randausgleich' wurde gewaehlt.}%   \RequirePackage[activate]{pdfcprot}}   {}  \ifthenelse{\value{Tabellen}=1}   {\typeout{Paket tah Meldung: Die Option `tabellen' wurde gewaehlt.}%   \RequirePackage{tabularx}   \RequirePackage{ragged2e}   \RequirePackage{dcolumn}   \RequirePackage{booktabs}   \newcolumntype{L}{&gt;{\RaggedRight\hspace{0pt}\arraybackslash}l}   \newcolumntype{Y}{&gt;{\RaggedRight\hspace{0pt}\arraybackslash}X}   \newcolumntype{d}[1]{&gt;{\DC@{.}{,}{#1}}l&lt;{\DC@end}}   }   {}    \endinput   I also don't really need all the features. So it would be nice to reduce it to minimal features, which are needed.. Do creatures that enter the battlefield at the same time see each other enter? Remove Meta Privilege for MSE (only) How to show that every Boolean ring is commutative? 16.04 new installation gives grub-efi-amd64-signed failed installation /target/ ubuntu 16.04 at the end Is it possible to get the data off of the hard drive of a PlayStation 3 that has crashed? I have already voided the warranty so I am not worried about that and I have access to quite a few tools.   I have a new PlayStation and a few saves that were not backed up. I am not worried about them but if it is possible I would love to get it moved over.   The old PlayStation will not turn on at all and I think I am going to have to pull the drive. My main concern is if I am able to transfer the files without running into any issues. I have heard that some of the stuff is specific to each PlayStation, is that true? How do I theme a webform? Is there a problem with Beamer in the latest MiKTeX update? This is about MiKTeX Revision 2.9.6360.  Immediately after the latest MiKTeX update, my Beamer files stopped compiling.  When i tried to compile a file that had been working fine I got a Package installation popup saying:  tex\latex\beamer\beamerbasemodes.sty  Is missing.  It is part of the following package  beamer   So i clicked to have it installed.  All that achieved is that i got an error message  ! LaTeX error: File 'beamerbasemodes.sty' not found   I repeated this a few times with minor changes to the file, and then went to the MiKTeX Package Manager to see what parts of Beamer are installed.  It said none were.  Either the update had removed Beamer, or the attempt to install beamerbasemodes on the fly had done it.  So I reinstalled it by hand.  In fact i did this several times in various ways.  It made one difference.  Sometimes the problem package was identified as  translator.sty  In case it would help, I ran Update FNDB and restarted my machine.  Each time I installed Beamer, the Package Manager then reported that Beamer was installed.    But when I tried to compile the file, the same things happened all over.   And when i went back to the MiKTeX Package Manager it reported Beamer is not installed.   Is Beamer now out of date?  Or is this a problem on the new update?  Is there a simple fix i can use? I run below command on ubuntu 16.4 :  sudo add-apt-repository ppa:noobslab/apps  of below question:    and get below error:  Traceback (most recent call last):   File "/usr/bin/add-apt-repository", line 11, in &lt;module&gt;     from softwareproperties.SoftwareProperties import SoftwareProperties, shortcut_handler   File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 27, in &lt;module&gt;     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg' Error in sys.excepthook: Traceback (most recent call last):   File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook     from apport.fileutils import likely_packaged, get_recent_crashes   File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in &lt;module&gt;     from apport.report import Report   File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in &lt;module&gt;     import apport.fileutils   File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in &lt;module&gt;     from apport.packaging_impl import impl as packaging   File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23, in &lt;module&gt;     import apt   File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in &lt;module&gt;     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'  Original exception was: Traceback (most recent call last):   File "/usr/bin/add-apt-repository", line 11, in &lt;module&gt;     from softwareproperties.SoftwareProperties import SoftwareProperties, shortcut_handler   File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 27, in &lt;module&gt;     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'   Thanks for help Extend x axis on graph? I'd like to extend my x axis a little longer. Is it possible to do that?  \centering     \begin{tikzpicture}[scale=1.5]      \begin{axis}[         xlabel=Reynolds Number,ylabel=Coefficient Discharge]     \addplot [color=blue,mark=*] coordinates {         (6485.41491,0.408143397)         (7927.942858,0.407370795)         (8663.115504,0.38550864)         (9219.462371,0.366953133)         (9537.374867,0.346531912)         (10491.11235,0.330115983)         (11087.19828,0.312041115)         (12219.76155,0.313951177)     };         \addlegendentry{1/4}     \addplot [color=red,mark=triangle] coordinates {         (6556.945221,   0.412644978)         (7868.334265,   0.404307857)         (8663.115504,   0.38550864)         (9187.671122,   0.365687778)         (9120.114717,   0.331371141)         (10443.42548,   0.328615455)         (11683.28421,   0.328817519)         (12875.45607,   0.330797337)     };         \addlegendentry{1/2 Lift}     \addplot [color=black,mark=*] coordinates {         (6843.066467,   0.430651305)         (8297.516134,   0.426361012)         (9203.566747,   0.40955872)         (8615.42863,    0.342911376)         (9298.940495,   0.337868614)         (10824.92047,   0.340619673)         (11683.28421,   0.328817519)         (12899.29951,   0.331409925)     };         \addlegendentry{3/4 Lift}     \addplot [color=yellow,mark=*] coordinates {         (6854.988186,   0.431401568)         (8398.850742,   0.431568008)         (9267.149246,   0.412388141)         (8567.741755,   0.341013343)         (9346.62737 ,   0.339601273)         (10753.39016,   0.338368882)         (11897.87515,   0.334857025)         (13030.43841,   0.334779157)     };         \addlegendentry{Full Lift}     \end{axis}% \end{tikzpicture}% How to get the Infobox data from Wikipedia? Star rating in AJAX with Ruby On Rails I've been wondering this for a while, why is there free space at the end of a drive that was formatted to NTFS in windows?  You can only see the unallocated space in Linux. So why is it there? Does it serve a purpose? Linearlayout order is reversed on some devices