diff --git a/CHANGELOG.md b/CHANGELOG.md
index 00fa75dbda7..577c529dc2b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,7 +35,8 @@ to [sourceforge feature requests](https://sourceforge.net/p/jabref/features/) by
 - Integrity check now also checks broken file links, abbreviations in journal and booktitle, and incorrect use of proceedings with page numbers
 
 ### Fixed
-- Fixed [#883](https://github.com/JabRef/jabref/issues/883): No NPE during cleanup 
+- Fixed [#598](https://github.com/JabRef/jabref/issues/598) and [#402](https://github.com/JabRef/jabref/issues/402): No more issues with invalid icons for ExternalFileTypes in global search or after editing the settings
+- Fixed [#883](https://github.com/JabRef/jabref/issues/883): No NPE during cleanup
 - Fixed [#466](https://github.com/JabRef/jabref/issues/466): Rename PDF cleanup now also changes case of file name
 - Fixed [#621](https://github.com/JabRef/jabref/issues/621) and [#669](https://github.com/JabRef/jabref/issues/669): Encoding and preamble now end with newline.
 - Make BibTex parser more robust against missing newlines
diff --git a/src/main/java/net/sf/jabref/external/ExternalFileType.java b/src/main/java/net/sf/jabref/external/ExternalFileType.java
index 96b8b441cc6..77c79987d84 100644
--- a/src/main/java/net/sf/jabref/external/ExternalFileType.java
+++ b/src/main/java/net/sf/jabref/external/ExternalFileType.java
@@ -80,10 +80,15 @@ public static ExternalFileType buildFromArgs(String[] val) {
             iconName = val[4];
         }
 
-        if ("new".equals(iconName)) {
-            icon = IconTheme.JabRefIcon.FILE.getSmallIcon();
-        } else {
-            icon = IconTheme.getImage(iconName);
+        // set icon to default first
+        icon = IconTheme.JabRefIcon.FILE.getSmallIcon();
+
+        // check whether there is another icon defined for this file type
+        for(ExternalFileType fileType : ExternalFileTypes.getDefaultExternalFileTypes()) {
+            if(fileType.getName().equals(name)) {
+                icon = fileType.icon;
+                break;
+            }
         }
 
         return new ExternalFileType(name, extension, mimeType, openWith, iconName, icon);
diff --git a/src/main/java/net/sf/jabref/external/ExternalFileTypeEditor.java b/src/main/java/net/sf/jabref/external/ExternalFileTypeEditor.java
index 56912b53027..eda2273658a 100644
--- a/src/main/java/net/sf/jabref/external/ExternalFileTypeEditor.java
+++ b/src/main/java/net/sf/jabref/external/ExternalFileTypeEditor.java
@@ -110,7 +110,7 @@ public void actionPerformed(ActionEvent e) {
                     Globals.lang("Reset file type definitions"), JOptionPane.YES_NO_OPTION,
                     JOptionPane.QUESTION_MESSAGE);*/
             //if (reply == JOptionPane.YES_OPTION) {
-            List<ExternalFileType> list = ExternalFileTypes.getInstance().getDefaultExternalFileTypes();
+            List<ExternalFileType> list = ExternalFileTypes.getDefaultExternalFileTypes();
             fileTypes.clear();
             fileTypes.addAll(list);
             Collections.sort(fileTypes);
diff --git a/src/main/java/net/sf/jabref/external/ExternalFileTypes.java b/src/main/java/net/sf/jabref/external/ExternalFileTypes.java
index b0b69b52ebd..89d72493676 100644
--- a/src/main/java/net/sf/jabref/external/ExternalFileTypes.java
+++ b/src/main/java/net/sf/jabref/external/ExternalFileTypes.java
@@ -40,7 +40,7 @@ private ExternalFileTypes() {
         updateExternalFileTypes();
     }
 
-    public List<ExternalFileType> getDefaultExternalFileTypes() {
+    public static List<ExternalFileType> getDefaultExternalFileTypes() {
         List<ExternalFileType> list = new ArrayList<>();
         list.add(new ExternalFileType("PDF", "pdf", "application/pdf", "evince", "pdfSmall",
                 IconTheme.JabRefIcon.PDF_FILE.getSmallIcon()));
diff --git a/src/main/java/net/sf/jabref/external/UnknownExternalFileType.java b/src/main/java/net/sf/jabref/external/UnknownExternalFileType.java
index 257b4c23af0..98da42715d4 100644
--- a/src/main/java/net/sf/jabref/external/UnknownExternalFileType.java
+++ b/src/main/java/net/sf/jabref/external/UnknownExternalFileType.java
@@ -25,7 +25,7 @@
 public class UnknownExternalFileType extends ExternalFileType {
 
     public UnknownExternalFileType(String name) {
-        super(name, "", "", "", "unknown", IconTheme.getImage("unknown"));
+        super(name, "", "", "", "unknown", IconTheme.JabRefIcon.FILE.getSmallIcon());
     }
 
 }
diff --git a/src/main/java/net/sf/jabref/gui/maintable/SpecialMainTableColumns.java b/src/main/java/net/sf/jabref/gui/maintable/SpecialMainTableColumns.java
index 91e4aa69dd4..c5f8ebf0f4d 100644
--- a/src/main/java/net/sf/jabref/gui/maintable/SpecialMainTableColumns.java
+++ b/src/main/java/net/sf/jabref/gui/maintable/SpecialMainTableColumns.java
@@ -104,6 +104,8 @@ public Object getColumnValue(BibEntry entry) {
                 ExternalFileType type = fileList.getEntry(0).type;
                 if (type != null) {
                     return type.getIconLabel();
+                } else {
+                    return new JLabel(IconTheme.JabRefIcon.FILE.getSmallIcon());
                 }
             }
 
diff --git a/src/main/java/net/sf/jabref/gui/search/SearchResultsDialog.java b/src/main/java/net/sf/jabref/gui/search/SearchResultsDialog.java
index 14fbdf84496..0e10ce0b7de 100644
--- a/src/main/java/net/sf/jabref/gui/search/SearchResultsDialog.java
+++ b/src/main/java/net/sf/jabref/gui/search/SearchResultsDialog.java
@@ -462,7 +462,11 @@ public Object getColumnValue(BibEntry entry, int column) {
                         tmpModel.setContent(entry.getField(Globals.FILE_FIELD));
                         fileLabel.setToolTipText(tmpModel.getToolTipHTMLRepresentation());
                         if (tmpModel.getRowCount() > 0) {
-                            fileLabel.setIcon(tmpModel.getEntry(0).type.getIcon());
+                            if(tmpModel.getEntry(0).type!=null) {
+                                fileLabel.setIcon(tmpModel.getEntry(0).type.getIcon());
+                            } else {
+                                fileLabel.setIcon(IconTheme.JabRefIcon.FILE.getSmallIcon());
+                            }
                         }
                         return fileLabel;
                     } else {