Tibco Jaspersoft + Oracle Apex Jasper Integration help debug

HI, I need help with debugging my setup.

I have an Oracle Apex install on Oracle Cloud Always free. Jasper Reports Integration (provided by Opal-Consulting) installed on a Oracle Cloud Compute instance under Apache Tomcat/9.0.54

I am creating Jasper reports with TIBCO Jaspersoft® Studio 6.18.1

Reports used to work until a few days ago. Now I am getting the following error:
HTTP Status 500 – Internal Server Error
Type Exception Report
Message Error compiling /u01/jri/reports/1.jrxml: Error saving file: /u01/jri/reports/1.jasper.
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
java.lang.RuntimeException: Error compiling /u01/jri/reports/1.jrxml: Error saving file: /u01/jri/reports/1.jasper.
de.oc.jasper.ReportUtilities.compileJRXMLIfNecessary(ReportUtilities.java:117)
de.oc.integration.jasper.webapp.ReportWrapper.service(ReportWrapper.java:182)
javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Note The full stack trace of the root cause is available in the server logs.

I pinpointed the issue to the report Details band. Without Details band, it works. With Details band, it stops working.

I will give you remote access to investigate,I need help how to fix this.
Project fixed : 20$