I tried using apacite, then decided it was too complex for me as a beginner, so I reverted to natbib and a plain bibliography style. But now \cite won't work anymore.

The displayed errors are:

Undefined control sequence. \cite{Boeing}
Missing number, treated as zero. \cite{Boeing}

I checked my bibliography and everything seems to be in order. But for what it's worth I'll put it in below along with the packages I'm using.



.bib file

  author     = "Boeing",
  title  = "Boeing-787-Ultimate-Load-Wing-Test-Completed",
  url    = "http://i1-news.softpedia-static.com/images/news2/Boeing-787-Ultimate-Load-Wing-Test-Completed-2.jpg"

  author    = "Efunda",
  title     = "Strain Gage: Materials",
  url       = "http://www.efunda.com/designstandards/sensors/strain_gages/strain_gage_selection_matl.cfm"

  author     = "The Engineering Toolbox",
  title  = "American Wide Flange Steel Beams, Retrieved December 6, 2015, from ",
  url    = "http://docs.engineeringtoolbox.com/documents/1313/steel-beam.png"

  title="Process control instrumentation technology",
  author="Johnson, Curtis D",
  publisher="Prentice Hall PTR"

  author = "All About Circuits",
  title  = "Chapter 9 - Electrical Instrumentation Signals - Strain Gauges, ",
  url      = "http://www.allaboutcircuits.com/textbook/direct-current/chpt-9/strain-gauges/"    

Thanks for any and all input. I am using TeXStudio for the record. I also notice that in the .aux file this was appearing:

\bibcite{Boeing}{{1}{{\APACyear {{\bibnodate {}}}}}{{Boeing}}{{Boeing}}}

for each entry. Does this mean that the effects of apacite are still in order on my document? Sorry if the format of this question is messy, I just started learnging latex and it is my first time here.

closed as off-topic by Mike Renfro, R. Schumacher, user13907, Au101, Stefan Pinnow Dec 6 '16 at 5:29

  • This question does not fall within the scope of TeX, LaTeX or related typesetting systems as defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

  • Welcome to TeX.SX! I have edited your question a bit to make it more readable (code can be indented by four spaces to make it monospaced, inline code can be set in ...), I have also re-tagged it because it is evidently not about biblatex. – moewe Dec 6 '15 at 17:28
  • welcome to the site but it is very hard to help if you do not give code that reproduces the error, or show the error that tex gives. the error messages you quote are not in the format tex uses (and lack information to diagnose the problem) probably it is a summary view from your editor, it would help to see the actual error lines from the log file, in a code section so that line breaks are preserved – David Carlisle Dec 6 '15 at 17:29
  • 1
    Have you tried deleting the temporary .aux file as well as the .bbl? If you switch packages the temporary files might contain stuff the new packages cannot deal with. – moewe Dec 6 '15 at 17:30
  • 1
    When switching from one bibliography and citation management package to another (here: from apacite to natbib), it's usually necessary to delete the .aux file and then re-run LaTeX, BibTeX, and the LaTeX twice more. The reason for having to delete the .aux file is that the apacite package employs instructions, such as \APACyear and \bibnodate, which aren't recognized by natbib. – Mico Dec 6 '15 at 17:34
  • 4
    I'm voting to close this question as off-topic because it's solved in comments by deleting aux files. – Mike Renfro Dec 6 '16 at 0:44

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