Error when trying to export Tempo Report to PDF

Some users receive a 500 error when they try to export a Tempo Report to PDF

The error message shows:
An error occurred during export. Threw exception org.apache.fop.apps.FOPException: .fop (Permission denied)

This problem is not a specific Tempo problem but is connected to the permissions that a user has for the .fop directory. To fix this, you might need to involve your System Administrator.

The problem occurs when the user that runs the Jira process does not have the correct permission in the ~/.fop directory. Normally this directory is located in the user home temporary folder.

In this case could you please make sure that the tmp folder in the Jira process user home has the correct permission setting so that the user can write in the directory (please note that the this directory is by default hidden).

The folder in question is Apache’s cache folder, and it’s outside the scope of Tempo Support. We have googled a bit and found this article: https://xmlgraphics.apache.org/fop/2.1/fonts.html. In it, under “The font cache” section, it says “Apache FOP maintains a cache file that is used to speed up auto-detection. This file is usually found in the “.fop” directory under the user’s home directory. It’s called “fop-fonts.cache”. When the user’s home directory is not writable, the font cache file is put in the directory for temporary files.” If you don’t find this folder, you might need to install FOP as described here: https://xmlgraphics.apache.org/fop/quickstartguide.html.