diff --git a/installAndRun.sh b/installAndRun.sh
index b1f320b..9f712ad 100755
--- a/installAndRun.sh
+++ b/installAndRun.sh
@@ -35,6 +35,7 @@ if [[ justInstall -eq 0 ]]; then
     echo -e "\nAsking for sudo, in order to install 'gradle'..\n"
     sudo mkdir /opt/gradle
     sudo apt install -y unzip && sudo unzip -d /opt/gradle gradle-${gradleVersion}-bin.zip
+    sudo rm -rf gradle-${gradleVersion}-bin.zip
     #ls /opt/gradle/gradle-${gradleVersion}  # For debugging installation
   fi
 
diff --git a/src/main/java/eu/openaire/urls_controller/controllers/BulkImportController.java b/src/main/java/eu/openaire/urls_controller/controllers/BulkImportController.java
index 9916d82..f8931d2 100644
--- a/src/main/java/eu/openaire/urls_controller/controllers/BulkImportController.java
+++ b/src/main/java/eu/openaire/urls_controller/controllers/BulkImportController.java
@@ -201,7 +201,7 @@ public class BulkImportController {
             bulkImportService.bulkImportFullTextsFromDirectory(bulkImportReport, finalRelativeBulkImportDir, finalBulkImportDir, givenDir, provenance, bulkImportSource, shouldDeleteFilesOnFinish)
         );
 
-        return ResponseEntity.ok().body(new BulkImportResponse(msg, bulkImportReportID));
+        return ResponseEntity.ok().body(new BulkImportResponse(msg, bulkImportReportID));   // The response is automatically serialized to json and it's of type "application/json".
     }
 
 
diff --git a/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java b/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
index 5768c8b..119e879 100644
--- a/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
+++ b/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
@@ -311,17 +311,17 @@ public class UrlsServiceImpl implements UrlsService {
 
         logger.debug("Going to write the results in the parquet files, then upload them to HDFS, and then load them into the database's tables. For batch-assignments_" + curReportAssignmentsCounter);
 
-        List<Callable<ParquetReport>> callableTasks = parquetFileUtils.getTasksForCreatingAndUploadingParquetFiles(urlReports, sizeOfUrlReports, curReportAssignmentsCounter, localParquetPath, uploadFullTextsResponse);
-
         // Create HDFS subDirs for these assignments. Other background threads handling other assignments will not interfere with loading of parquetFiles to the DB tables.
         String endingMkDirAndParams = curReportAssignmentsCounter + "/" + parquetFileUtils.mkDirsAndParams;
         if ( !parquetFileUtils.applyHDFOperation(parquetFileUtils.webHDFSBaseUrl + parquetFileUtils.parquetHDFSDirectoryPathAttempts + endingMkDirAndParams)
-            || !parquetFileUtils.applyHDFOperation(parquetFileUtils.webHDFSBaseUrl + parquetFileUtils.parquetHDFSDirectoryPathPayloadsAggregated + endingMkDirAndParams) )
+                || !parquetFileUtils.applyHDFOperation(parquetFileUtils.webHDFSBaseUrl + parquetFileUtils.parquetHDFSDirectoryPathPayloadsAggregated + endingMkDirAndParams) )
         {
             postReportResultToWorker(curWorkerId, curReportAssignmentsCounter, "Error when creating the HDFS sub-directories for assignments_" + curReportAssignmentsCounter);
             return false;
         }
 
+        List<Callable<ParquetReport>> callableTasks = parquetFileUtils.getTasksForCreatingAndUploadingParquetFiles(urlReports, sizeOfUrlReports, curReportAssignmentsCounter, localParquetPath, uploadFullTextsResponse);
+
         boolean hasAttemptParquetFileProblem = false;
         boolean hasPayloadParquetFileProblem = false;