Currently arXiv compiles LaTeX projects using a modified version of TeX Live 2020. For projects that use a more recent version of TeX Live, this can result in incompatibilities when submitting to arXiv. On Overleaf, you're able to select the version of TeX Live used to compile your project which allows you to choose the most compatible version of TeX Live available for arXiv submissions.
In addition, some projects that compile without errors on Overleaf may encounter unexpected compilation errors when submitted to the arXiv service. This help page outlines some common reasons, and how to solve them.
At the time of writing (October 2020) the arXiv service uses a version of TeX Live 2020 to process LaTeX submissions. New Overleaf projects (either created from scratch or when you clone a project) are now based on TeX Live 2020, but older projects may be using another TeX Live image. Users wishing to submit an Overleaf project to arXiv can be affected by this mismatch in TeX Live versions due to unavoidable differences in some LaTeX packages.
To address this issue, Overleaf users wishing to submit their work to arXiv should ensure they are using Tex Live 2020 by using Overleaf's TeX Live selection feature.
hyperref package?When processing LaTeX submissions, arXiv loads the hyperref package with its required set of options. If your project also loads hyperref with options, you may then get an “Option clash for package hyperref” error on your arXiv submission.
You can try setting your hyperref options separately from the package loading. For example, the line
\usepackage[colorlinks,allcolors=black,pdftex]{hyperref}
can be changed to
\usepackage{hyperref}
\hypersetup{colorlinks,allcolors=black}
Note that it is not necessary (nor recommended) to specify the pdftex (nor dvips, dvipdfm, ...) option for hyperref nor for other packages.
If the hyperref package is loaded by a document class or a package then it may not be feasible to change how hyperref options are loaded. One example is if you're using \documentclass{mnras}. In such cases you may have to prevent arXiv from injecting its hyperref commands. This can be done by adding a file to your project named 00README.XXX and putting this line in it:
nohypertex
.tex file on the project’s top level?arXiv submissions might not compile where the main .tex file is inside a folder, so before re-attempting submission to arXiv try moving that .tex file to the root-level of your Overleaf project. Remember that you may also need to update file paths for your \include, \input, \includegraphics and \bibliography commands, etc.
.eps image files alongside .png, .jpg or .pdf image files?arXiv will use pdfLaTeX to process your submissions and, of course, pdfLaTeX cannot directly incorporate .eps graphics files into the typeset PDF: they must first be converted to a format that pdfLaTeX can use. Overleaf can automatically convert .eps files to .pdf format during pdfLaTeX compilation but arXiv may not have this feature enabled. Consequently, arXiv’s compilation might generate errors with commands that try to include .eps files, such as \includegraphics{plot.eps}.
If your Overleaf project uses graphics in .eps format we recommend that you convert them to .pdf format, upload them to your project and use the .pdf versions directly within any \includegraphics commands in your document.