Guide to LaTeX (4th Edition) (Tools and Techniques

424 Appendix C. Error Messages
! LaTeX Error: The font size command \normalsize is not defined:
there is probably something wrong with class file.
It is necessary for class files to define \normalsize, the basic size of standard
text in the document. If the class file does not do this, if it only
defines \@normalsize, then it must be repaired. This message also appears
if \documentclass is missing, for an empty class file is clearly a
faulty one.
! LaTeX Error: This NFSS system isn’t set up properly.
Something is wrong with the font descriptions in the.fd files, or there is
no valid font declared by \DeclareErrorFont. This is a serious problem,
to be reported to the system manager.
! LaTeX Error: Too many math alphabets used in version ....
There is a limit of 16 math alphabets possible, a number set by T E X itself.
Any additional math alphabet definitions are ignored.
! LaTeX Error: Unknown symbol font ‘...’.
The name of a non-existent symbol font has been used as argument to
the command \DeclareSymbolFontAlphabet. The font name must first
be declared with \DeclareSymbolFont before it may be used.
C.4 T E X error messages
This section contains a list of some of the most common T E X error messages,
ordered alphabetically according to the error indicator, together
with a brief description of the possible cause. Each one begins with an
exclamation point only.
! Counter too large.
As a T E X error, this message refers to a footnote marked either with letters
or symbols in which the counter has exceeded a value of 26 or 9. It may
also occur if there are too many \thanks commands on a title page.
! Double subscript.
A mathematical formula contains two subscripts for the same variable,
for example, x_2_3 or x_{2}_{3}. The proper way to produce x23 is with
x_{2_3} or x_{2_{3}} (Section 5.2.2).
! Double superscript.
A mathematical formula contains two superscripts for the same variable,
for example, xˆ2ˆ3 or xˆ{2}ˆ{3}. The proper way to produce x23 is with
xˆ{2ˆ3} or xˆ{2ˆ{3}} (Section 5.2.2).