diff --git a/build.gradle b/build.gradle
index 76d0ca6..e9c664c 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,7 +8,6 @@ group = 'eu.openaire.urls_worker'
 version = '1.0.0-SNAPSHOT'
 sourceCompatibility = '1.8'
 
-
 repositories {
     mavenCentral()
     flatDir {
@@ -16,7 +15,6 @@ repositories {
     }
 }
 
-
 dependencies {
     runtimeOnly "org.springframework.boot:spring-boot-devtools"
 
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 84d1f85..d2880ba 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/installAndRun.sh b/installAndRun.sh
index 60ffd25..4d9500c 100755
--- a/installAndRun.sh
+++ b/installAndRun.sh
@@ -28,7 +28,7 @@ if [[ ! -f $inputDataFile ]]; then
   echo -e "\n\n"
 fi
 
-gradleVersion="7.3.1"
+gradleVersion="7.3.2"
 
 if [[ justInstall -eq 0 ]]; then
 
@@ -63,6 +63,13 @@ if [[ justInstall -eq 0 ]]; then
 
   export PATH=$PATH:/opt/gradle/gradle-${gradleVersion}/bin
 
+  # Update the max-heap-size based on the machine's physical memory.
+  machine_memory_mb=$(grep MemTotal /proc/meminfo | awk '{print $2}' | xargs -I {} echo "scale=4; {}/1024" | bc)  # It returns the size in MB.
+  max_heap_size_mb=$(echo "($machine_memory_mb - 768)/1" | bc) # Leave 768 MB to the system (the "()/1" is used to take the floor value).
+  # Now, we replace the "-Xmx" parameter inside the "./build.gradle" file, with "-Xmx${max_heap_size}m"
+  echo -e "\n\nThe max-heap-size (-Xmx) will be set to: ${max_heap_size_mb}m\n\n"
+  sed -i "s/'-Xmx[0-9]\+[gm]'/'-Xmx${max_heap_size_mb}m'/g" ./build.gradle
+
   gradle wrapper --gradle-version=${gradleVersion} --distribution-type=bin
 
   #gradle tasks  # For debugging installation
diff --git a/src/main/java/eu/openaire/urls_worker/plugins/PublicationsRetrieverPlugin.java b/src/main/java/eu/openaire/urls_worker/plugins/PublicationsRetrieverPlugin.java
index 3b8d8ec..d57d55f 100644
--- a/src/main/java/eu/openaire/urls_worker/plugins/PublicationsRetrieverPlugin.java
+++ b/src/main/java/eu/openaire/urls_worker/plugins/PublicationsRetrieverPlugin.java
@@ -2,7 +2,6 @@ package eu.openaire.urls_worker.plugins;
 
 import edu.uci.ics.crawler4j.url.URLCanonicalizer;
 import eu.openaire.publications_retriever.PublicationsRetriever;
-import eu.openaire.publications_retriever.exceptions.DocFileNotRetrievedException;
 import eu.openaire.publications_retriever.util.file.FileUtils;
 import eu.openaire.publications_retriever.util.http.ConnSupportUtils;
 import eu.openaire.publications_retriever.util.http.HttpConnUtils;
@@ -136,8 +135,6 @@ public class PublicationsRetrieverPlugin {
     }
 
 
-    private static final String DocFileNotRetrievedExceptionName = DocFileNotRetrievedException.class.getSimpleName();  // Keep it here for easily spot if the exception changes inside the PublicationsRetriever library.
-
     public static void addUrlReportsToWorkerReport()
     {
         Timestamp timestamp = new Timestamp(System.currentTimeMillis()); // Store it here, in order to have the same for all current records.
@@ -149,7 +146,7 @@ public class PublicationsRetrieverPlugin {
             Long size = data.getSize();
             Error error = null;
 
-            if ( data.getWasDocumentOrDatasetAccessible().equals("true") )
+            if ( "true".equals(data.getWasDocumentOrDatasetAccessible()) )  // The reversed order defends against a potential NPE.
             {
                 status = UrlReport.StatusType.accessible;
                 if ( comment.contains(UrlUtils.alreadyDownloadedByIDMessage) ) {
@@ -168,15 +165,18 @@ public class PublicationsRetrieverPlugin {
                     }
                     // TODO - The case where the "twin-ID" is not found, should "never" happen. But should we check? How to handle if that is the case..?
                 }
-                else if ( ! comment.contains(DocFileNotRetrievedExceptionName) ) {  // If it was downloaded without an error.
+                else if ( ! comment.equals(HttpConnUtils.docFileNotRetrievedMessage) ) {  // If it was downloaded without an error.
                     fileLocation = comment; // This is the full-file-path.
                     mimeType = "application/pdf";
-                }
-                error = new Error(null, null);  // We do not want to send a "null" object, since it just adds more complicated handling in the controller..
+                } else  // Else the file was not retrieved, so all file-related data are kept "null".
+                    error = new Error(Error.ErrorType.couldRetry, comment); // We can still try to download it in the future.
+
+                if ( error == null )    // If the file was retrieved, in any time.
+                    error = new Error(Error.ErrorType.couldRetry, null);  // We do not want to send a "null" object, since it just adds more complicated handling in the controller..
             }
             else {
                 status = UrlReport.StatusType.non_accessible;
-                if ( data.getCouldRetry().equals("true") )
+                if ( "true".equals(data.getCouldRetry()) )
                     error = new Error(Error.ErrorType.couldRetry, comment);
                 else
                     error = new Error(Error.ErrorType.noRetry, comment);