New error messages

LATEX2e has a number of new error messages. Please also note that many error messages now produce further helpful information if you press |h| in response to the error prompt.
\begin{decl}
\vert Option clash for package \vert\m {package}\vert.\vert
\end{decl}
The named package has been loaded twice with different options. If you enter |h| you will be told what the options were, for example, if your document contained:
   \usepackage[foo]{fred}
   \usepackage[baz]{fred}
then you will get the error message:
   Option clash for package fred.
and typing |h| at the |?| prompt will give you:
   The package fred has already been loaded with options:
     [foo]
   There has now been an attempt to load it with options:
     [baz]
   Adding the line:
     \usepackage[foo,baz]{fred}
   to your document may fix this.
   Try typing <<return>> to proceed.
The cure is, as suggested, to load the package with both sets of options. Note that since LATEX packages can call other packages, it is possible to get a package option clash without explicitly requesting the same package twice.
\begin{decl}
\vert Command \vert\m {command}\vert not provided in base NFSS.\vert
\end{decl}
The command is not provided by default in LATEX2e. This error is generated by using one of the commands:
   \mho \Join \Box \Diamond \leadsto
   \sqsubset \sqsupset \lhd \unlhd \rhd \unrhd
which are now part of the |latexsym| package. The cure is to add:
   \usepackage{latexsym}
in the preamble of your document.
\begin{decl}
\vert LaTeX2e command <command> in LaTeX 2.09 document.\vert
\end{decl}
The command is a LATEX2e command but this is a LATEX 2.09 document. The cure is to replace the command by a LATEX 2.09 command, or to run document in native mode, as described in Section [*].
\begin{decl}
\vert NFSS release 1 command \newmathalphabet found.\vert
\end{decl}
The command || was used by the New Font Selection Scheme Release 1 but it has now been replaced by | |, the use of which is described in
. The best cure is to update the package which contained the || command. Find out if there is a new release of the package, or (if you wrote the package yourself) consult for the new syntax of font commands. If there is no updated version of the package then you can cure this error by using the |newlfont| or |oldlfont| package, which tells LATEX which version of || should be emulated. You should use |oldlfont| if the document selects math fonts with syntax such as this:
|A|, etc.
Use |newlfont| if the document's syntax is like this:
|A|, etc.

\begin{decl}
\vert Text for \verb command ended by end of line.\vert
\end{decl}
The | command has been begun but not ended on that line. This usually means that you have forgotten to put in the end-character of the command. \begin{decl} Illegal use of command.| The | command has been used inside the argument of another command. This has never been allowed in \LaTeX{}---often producing incorrect output without any warning---and so \LaTeXe{} produces an error message. \subsection{Old internal commands} \label{Sec:oldinternals} A number of \LaTeX~2.09 internal commands have been removed, since their functionality is now provided in a different way. See \emph{\clsguide} for more details of the new, supported interface for class and package writers. \begin{decl} | || || ...
|| || || ...
|| || || ...
$\vdots$ These commands provided access to the seventy fonts pre-loaded by LATEX 2.09. In contrast, LATEX2e normally pre-loads at most fourteen fonts, which saves a lot of font memory; but a consequence is that any LATEX file which used the above commands to directly access fonts will no longer work. Their use will usually produce an error message such as:
   ! Undefined control sequence.
   l.5 \tenrm
The cure for this is to update the document to use the new font-changing commands provided by LATEX2e; these are described in . If this is not possible then, as a last resort, you can use the |rawfonts| package, which loads the seventy LATEX 2.09 fonts and provides direct access to them using the old commands. This takes both time and memory. If you do not wish to load all seventy fonts, you can select some of them by using the |only| option to |rawfonts|. For example, to load only |tenrm| and |tenbf| you write:
   \usepackage[only,tenrm,tenbf]{rawfonts}
The |rawfonts| package is distributed with the LATEX tools software, see Section [*].