It looks like the document class may fail to define a page style called myheadings. Which document class do you employ?
– MicoJan 24 '21 at 16:48
You are using a document class which does not define the myheadings page style. Change document class or delete \pagestyle{myheadings}
– IvanJan 24 '21 at 16:54
@Mico i defined this package in the main page \documentclass[12pt,a4paper,twosided]{book}
\usepackage[centertags]{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{graphics}
\usepackage{newlfont}
\usepackage{xthesis}
\usepackage{xtocinc}
\pagestyle{headings} \hfuzz2pt
– blue-FJan 24 '21 at 17:25
1
you are trying to compile the chapter file. Set the main file as "main file", so that it is compiled.
– Ulrike FischerJan 24 '21 at 17:46
Please follow up on what @leandriis has asked you to do -- to post not just a screenshot of some code, but the actual code that gives rise to the issue you're looking to fix.
– MicoJan 24 '21 at 18:02
In your comment, you mention that \pagestyle{headings} is in the preamble, yet the screenshot you posted says something about the myheadings style not being found. Please clarify.
– MicoJan 24 '21 at 18:04
I’m voting to close this question because I'm voting to close this question because suggestions given i comments were acknowledged by OP to solve the problem.
– barbara beetonJan 24 '21 at 20:46
$$, you might nevertheless want to take a look at What are the differences between $$, [, align, equation and displaymath? and Why is [ … ] preferable to $$ … $$? – leandriis Jan 24 '21 at 16:45myheadings. Which document class do you employ? – Mico Jan 24 '21 at 16:48myheadingspage style. Change document class or delete\pagestyle{myheadings}– Ivan Jan 24 '21 at 16:54\pagestyle{headings}is in the preamble, yet the screenshot you posted says something about themyheadingsstyle not being found. Please clarify. – Mico Jan 24 '21 at 18:04