After an upgrade to Jaspersoft 7.1, the Out of the Box (OOTB) reports work well. However, the custom content with images/files does not display and an error is thrown:
The server has encountered an error. Please excuse the inconvenience.
The same is working well in Jaspersoft 6.4.2.
Jaspersoft 7.1 and higher
There have been changes in how Jaspersoft evaluates the paths for different users. In older Jaspersoft versions, you could use the absolute path for the resources and these absolute paths were resolved for the organizational users but that was deemed to be a potential security risk. The main idea is that the users should not know about the existence of anything else in the server other than their organization and its sub-organizations and public folder.
The absolute path now only resolves for superuser, and other users on the root level, if you have any. Superuser is intended to be used for global server administration and not for running or deploying reports.
We recommend using relative paths such as: repo:/ca_ppm/resources/images/custom/Background.png
Also, ensure you always create a report developer user in the organization as per our Documentation: Create an Advanced Reporting Developer User