ERROR BaseExportImportCommand:45 - java.lang.NullPointerException: entry

Issue Description:

While importing the resource (export.zip) and got the below error.

Error Trace:
     [java] ERROR BaseExportImportCommand:45 - java.lang.NullPointerException: entry
     [java] java.lang.NullPointerException: entry
     [java]     at java.base/java.util.Objects.requireNonNull(Objects.java:246)
     [java]     at java.base/java.util.zip.ZipFile.getInputStream(ZipFile.java:371)
     [java]     at com.jaspersoft.jasperserver.export.io.ZipFileInput.getFileInputStream(ZipFileInput.java:74)
     [java]     at com.jaspersoft.jasperserver.export.ImporterImpl.getInput(ImporterImpl.java:277)
     [java]     at com.jaspersoft.jasperserver.export.ImporterImpl.readDocument(ImporterImpl.java:247)
     [java]     at com.jaspersoft.jasperserver.export.ImporterImpl.getImportInputMetadata(ImporterImpl.java:287)
     [java]     at com.jaspersoft.jasperserver.export.ImporterImpl.setTask(ImporterImpl.java:113)
     [java]     at com.jaspersoft.jasperserver.export.ImportCommandImpl.process(ImportCommandImpl.java:81)
     [java]     at com.jaspersoft.jasperserver.export.BaseExportImportCommand.process(BaseExportImportCommand.java:112)
     [java]     at com.jaspersoft.jasperserver.export.ImportCommand.main(ImportCommand.java:43)
     
Resolution:

The repository export zip file does not contain the index.xml file, which is missing and it seems the export was not done successfully.

usually, this issue comes across when the server is on the VM, so we are unable to export successfully somehow.

As a workaround tried exporting an organization/s level export and importing it into the target JRS version and it worked fine. 

Please try first on the test/dev environment and then on the production environment. thanks!