[#11241] - simple report empty / on error after jasperReport Server restart

Hi there :-)

At first information about our setup:
I use JasperReport Server Pro on an amd64 virtualized environment (CentOS 7.5) with Apache Tomcat/8.5.29 and OpenSDK 1.8.0_171-b10.
Pro info over Rest:

Edition=PRO;
version=7.1.0;
Build=20180810_0504;
dateFormatPattern=yyyy-MM-dd;
datetimeFormatPattern=yyyy-MM-dd'T'HH:mm:ss;
expiration=2019-07-10T01:59:00;
features=EXP Fusion AHD DB ;
licenseType=Kommerziell;

As Database we use Oracle version 11.2.0.2.0 (11/2) driver is Oracle version 5.1.4.000208 (F000209.U000089) (5/1) (got this from log)

Now the most important:
A Report is scheduled as job every day. If the jasperServer application restarts the very first dasboard has an error in an report-part.
The Dashboard has three elements that were created by adhoc report editor. All those reports are simple tables. The only "setting" I created was a filter for selecting one day before only.
The Error-Message on the report-space was "Ein nicht erklärter Fehler ist aufgetreten, und der Vorgang ist fehlgeschlagen" (similar to: "An unknown error occured and the process could'nt finish").
After a manually "reRun" of the job there was no problem anymore and the dashboard was sent with all content.

Here part of the Log-Information:
----------------------------------------------------------------------
2018-09-27 10:04:25,005 ERROR GroovyGenerator,pool-63-thread-1:242 - generated groovy:
import org.joda.time.*
import com.jaspersoft.commons.dataset.*
import com.jaspersoft.commons.datarator.*
import com.jaspersoft.commons.dimengine.*
import groovy_column.BaseGroovyColumn
class JRS_GenColumn extends BaseGroovyColumn {
def JRS_GenColumn() { super('java.lang.Double') }
Object getValue() {
return (java.lang.Double) null }
// define vars here!!!
void setDataSet(WorkingDataSet ds) {
super.setDataSet(ds)
// set vars here!!!
}
}

2018-09-27 10:04:25,006 ERROR AdhocDataSourceService,pool-63-thread-1:201 - java.lang.RuntimeException: exception getting agg column for expression 'null'
----------------------------------------------------------------------
If I can provide more information let me know.

Best wishes from Germany
Marco Hetzel