This troubleshooting guide lists a few common errors that you may encounter when using EPUBCheck. If you’d like to suggest another entry, or have a better solution for one of these, feel free to file an issue to GitHub!

§ “File not found” error

If EPUBCheck fails because of Unicode characters in file paths, the following command line parameters can be used:

For example (“Mały Książę” = “Le Petit Prince” in Polish):

java -Dsun.jnu.encoding=UTF8 -Dfile.encoding=UTF8 -jar epubcheck.jar "Mały Książę - Antoine de Saint-Exupéry.epub"

§ “Stack overflow” error

If EPUBCheck crashes with a StackOverflowError, try adjusting the thread stack size of your Java Virtual Machine. With most Java distributions, this can be done by using the -Xss option of the java command, like in the following example:

java -Xss1024k -jar epubcheck.jar moby-dick.epub