diff --git a/main/src/com/google/refine/ProjectManager.java b/main/src/com/google/refine/ProjectManager.java
index 8b016d175..66f2e6dcd 100644
--- a/main/src/com/google/refine/ProjectManager.java
+++ b/main/src/com/google/refine/ProjectManager.java
@@ -45,9 +45,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
-import org.apache.commons.lang.exception.ExceptionUtils;
 import org.apache.tools.tar.TarOutputStream;
-import org.json.JSONException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -418,15 +416,10 @@ public abstract class ProjectManager {
         
         initDisplay(jsonObjArray);
         
-        try {
-            String userMeta = (String)_preferenceStore.get(PreferenceStore.USER_METADATA_KEY);
-            if (userMeta == null)
-                return;
-            userMetadataPreference = ParsingUtilities.mapper.createArrayNode();
-        } catch (JSONException e1) {
-            logger.warn("wrong definition of userMetadata format. Please use form [{\"name\": \"client name\", \"display\":true}, {\"name\": \"progress\", \"display\":false}]");
-            logger.error(ExceptionUtils.getFullStackTrace(e1));
-        }
+        String userMeta = (String)_preferenceStore.get(PreferenceStore.USER_METADATA_KEY);
+        if (userMeta == null)
+            return;
+        userMetadataPreference = ParsingUtilities.mapper.createArrayNode();
         
         for (int index = 0; index < userMetadataPreference.size(); index++) {
             boolean found = false;
diff --git a/main/src/com/google/refine/commands/browsing/GetScatterplotCommand.java b/main/src/com/google/refine/commands/browsing/GetScatterplotCommand.java
index d54bf2230..6d0f87b08 100644
--- a/main/src/com/google/refine/commands/browsing/GetScatterplotCommand.java
+++ b/main/src/com/google/refine/commands/browsing/GetScatterplotCommand.java
@@ -44,7 +44,6 @@ import javax.servlet.ServletOutputStream;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import org.json.JSONException;
 import org.json.JSONObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -95,7 +94,7 @@ public class GetScatterplotCommand extends Command {
         }
     }
     
-    public void draw(OutputStream output, Project project, Engine engine, JSONObject o) throws IOException, JSONException {
+    public void draw(OutputStream output, Project project, Engine engine, JSONObject o) throws IOException {
 
         double min_x = 0;
         double min_y = 0;
diff --git a/main/src/com/google/refine/expr/functions/arrays/Join.java b/main/src/com/google/refine/expr/functions/arrays/Join.java
index 492ab9448..c59522231 100644
--- a/main/src/com/google/refine/expr/functions/arrays/Join.java
+++ b/main/src/com/google/refine/expr/functions/arrays/Join.java
@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.arrays;
 import java.util.List;
 import java.util.Properties;
 
-import org.json.JSONException;
-
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.ExpressionUtils;
@@ -75,12 +73,7 @@ public class Join implements Function {
                             if (sb.length() > 0) {
                                 sb.append(separator);
                             }
-                            try {
-                                sb.append(JsonValueConverter.convert(a.get(i)).toString());
-                            } catch (JSONException e) {
-                                return new EvalError(ControlFunctionRegistry.getFunctionName(this) + 
-                                    " cannot retrieve element " + i + " of array");
-                            }
+                            sb.append(JsonValueConverter.convert(a.get(i)).toString());
                         }
                     } else {
                         for (Object o : ExpressionUtils.toObjectList(v)) {
diff --git a/main/src/com/google/refine/importers/ExcelImporter.java b/main/src/com/google/refine/importers/ExcelImporter.java
index 8bce9bcad..173fc1e73 100644
--- a/main/src/com/google/refine/importers/ExcelImporter.java
+++ b/main/src/com/google/refine/importers/ExcelImporter.java
@@ -44,7 +44,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.apache.commons.lang.exception.ExceptionUtils;
 import org.apache.poi.POIXMLDocument;
 import org.apache.poi.POIXMLException;
 import org.apache.poi.common.usermodel.Hyperlink;
@@ -54,7 +53,6 @@ import org.apache.poi.poifs.filesystem.POIFSFileSystem;
 import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.usermodel.Workbook;
 import org.apache.poi.xssf.usermodel.XSSFWorkbook;
-import org.json.JSONException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -187,13 +185,9 @@ public class ExcelImporter extends TabularImportingParserBase {
         
         for(int i=0;i<sheets.size();i++)  {
             String[] fileNameAndSheetIndex = new String[2];
-            try {
-                ObjectNode sheetObj = (ObjectNode) sheets.get(i);
-                // value is fileName#sheetIndex
-                fileNameAndSheetIndex = sheetObj.get("fileNameAndSheetIndex").asText().split("#");
-            } catch (JSONException e) {
-                logger.error(ExceptionUtils.getFullStackTrace(e));
-            }
+            ObjectNode sheetObj = (ObjectNode) sheets.get(i);
+            // value is fileName#sheetIndex
+            fileNameAndSheetIndex = sheetObj.get("fileNameAndSheetIndex").asText().split("#");
             
             if (!fileNameAndSheetIndex[0].equals(fileSource))
                 continue;
diff --git a/main/src/com/google/refine/importers/ImportingParserBase.java b/main/src/com/google/refine/importers/ImportingParserBase.java
index fe0061f96..0ca2d066d 100644
--- a/main/src/com/google/refine/importers/ImportingParserBase.java
+++ b/main/src/com/google/refine/importers/ImportingParserBase.java
@@ -39,7 +39,6 @@ import java.io.InputStream;
 import java.io.Reader;
 import java.util.List;
 
-import org.json.JSONException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -150,12 +149,8 @@ abstract public class ImportingParserBase implements ImportingParser {
     }
 
     private void pushImportingOptions(ProjectMetadata metadata, String fileSource, ObjectNode options) {
-        try {
-            options.put("fileSource", fileSource);
-        } catch (JSONException e) {
-            // ignore
-        }
-     // set the import options to metadata:
+        options.put("fileSource", fileSource);
+        // set the import options to metadata:
         metadata.appendImportOptionMetadata(options);
     }
     
diff --git a/main/src/com/google/refine/importers/OdsImporter.java b/main/src/com/google/refine/importers/OdsImporter.java
index 48dbb6c34..581dc1aea 100644
--- a/main/src/com/google/refine/importers/OdsImporter.java
+++ b/main/src/com/google/refine/importers/OdsImporter.java
@@ -45,7 +45,6 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.commons.lang.exception.ExceptionUtils;
-import org.json.JSONException;
 import org.odftoolkit.odfdom.doc.OdfDocument;
 import org.odftoolkit.odfdom.doc.table.OdfTable;
 import org.odftoolkit.odfdom.doc.table.OdfTableCell;
@@ -146,14 +145,10 @@ public class OdsImporter extends TabularImportingParserBase {
         ArrayNode sheets = JSONUtilities.getArray(options, "sheets");
         for(int i=0;i<sheets.size();i++)  {
             String[] fileNameAndSheetIndex = new String[2];
-            try {
-                ObjectNode sheetObj = JSONUtilities.getObjectElement(sheets, i);
-                // value is fileName#sheetIndex
-                fileNameAndSheetIndex = sheetObj.get("fileNameAndSheetIndex").asText().split("#");
-            } catch (JSONException e) {
-                logger.error(ExceptionUtils.getFullStackTrace(e));
-            }
-            
+            ObjectNode sheetObj = JSONUtilities.getObjectElement(sheets, i);
+            // value is fileName#sheetIndex
+            fileNameAndSheetIndex = sheetObj.get("fileNameAndSheetIndex").asText().split("#");
+        
             if (!fileNameAndSheetIndex[0].equals(fileSource))
                 continue;
             
diff --git a/main/src/com/google/refine/io/FileProjectManager.java b/main/src/com/google/refine/io/FileProjectManager.java
index 71240ff60..271a4f5c6 100644
--- a/main/src/com/google/refine/io/FileProjectManager.java
+++ b/main/src/com/google/refine/io/FileProjectManager.java
@@ -50,7 +50,6 @@ import java.util.zip.GZIPOutputStream;
 import org.apache.tools.tar.TarEntry;
 import org.apache.tools.tar.TarInputStream;
 import org.apache.tools.tar.TarOutputStream;
-import org.json.JSONException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -296,7 +295,7 @@ public class FileProjectManager extends ProjectManager  {
         return projectSaveNeeded || _preferenceStore.isDirty();
     }
     
-    protected void saveProjectMetadata() throws JSONException, IOException {
+    protected void saveProjectMetadata() throws IOException {
         for(Entry<Long,ProjectMetadata> entry : _projectsMetadata.entrySet()) {
             ProjectMetadata metadata = entry.getValue();
             if (metadata != null && metadata.isDirty()) {
@@ -305,7 +304,7 @@ public class FileProjectManager extends ProjectManager  {
         }
     }
 
-    protected boolean saveToFile(File file) throws IOException, JSONException {
+    protected boolean saveToFile(File file) throws IOException {
         FileWriter writer = new FileWriter(file);
         boolean saveWasNeeded = saveNeeded();
         try {
diff --git a/main/src/com/google/refine/io/ProjectMetadataUtilities.java b/main/src/com/google/refine/io/ProjectMetadataUtilities.java
index 63601f3c9..61d5d227e 100644
--- a/main/src/com/google/refine/io/ProjectMetadataUtilities.java
+++ b/main/src/com/google/refine/io/ProjectMetadataUtilities.java
@@ -46,10 +46,6 @@ import java.util.List;
 
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.exception.ExceptionUtils;
-import org.json.JSONException;
-import org.json.JSONObject;
-import org.json.JSONTokener;
-import org.json.JSONWriter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -61,7 +57,7 @@ import com.google.refine.util.ParsingUtilities;
 public class ProjectMetadataUtilities {
     final static Logger logger = LoggerFactory.getLogger("project_metadata_utilities");
 
-    public static void save(ProjectMetadata projectMeta, File projectDir) throws JSONException, IOException  {
+    public static void save(ProjectMetadata projectMeta, File projectDir) throws IOException  {
         File tempFile = new File(projectDir, "metadata.temp.json");
         saveToFile(projectMeta, tempFile);
 
@@ -79,7 +75,7 @@ public class ProjectMetadataUtilities {
         tempFile.renameTo(file);
     }
     
-    protected static void saveToFile(ProjectMetadata projectMeta, File metadataFile) throws JSONException, IOException   {
+    protected static void saveToFile(ProjectMetadata projectMeta, File metadataFile) throws IOException   {
         Writer writer = new OutputStreamWriter(new FileOutputStream(metadataFile));
         try {
             ParsingUtilities.defaultWriter.writeValue(writer, projectMeta);
diff --git a/main/src/com/google/refine/operations/column/ColumnAdditionByFetchingURLsOperation.java b/main/src/com/google/refine/operations/column/ColumnAdditionByFetchingURLsOperation.java
index 4251235e5..a120d8651 100644
--- a/main/src/com/google/refine/operations/column/ColumnAdditionByFetchingURLsOperation.java
+++ b/main/src/com/google/refine/operations/column/ColumnAdditionByFetchingURLsOperation.java
@@ -45,8 +45,6 @@ import java.util.List;
 import java.util.Properties;
 import java.util.concurrent.TimeUnit;
 
-import org.json.JSONException;
-
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.cache.CacheBuilder;
@@ -224,7 +222,7 @@ public class ColumnAdditionByFetchingURLsOperation extends EngineDependentOperat
             Evaluable eval,
             String description,
             boolean cacheResponses
-        ) throws JSONException {
+        ) {
             super(description);
             _project = project;
             _engine = engine;
diff --git a/main/src/com/google/refine/operations/recon/ExtendDataOperation.java b/main/src/com/google/refine/operations/recon/ExtendDataOperation.java
index 670adda23..32dfe1538 100644
--- a/main/src/com/google/refine/operations/recon/ExtendDataOperation.java
+++ b/main/src/com/google/refine/operations/recon/ExtendDataOperation.java
@@ -41,8 +41,6 @@ import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
 
-import org.json.JSONException;
-
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.refine.browsing.Engine;
@@ -140,7 +138,7 @@ public class ExtendDataOperation extends EngineDependentOperation {
             Project project, 
             EngineConfig engineConfig, 
             String description
-        ) throws JSONException {
+        ) {
             super(description);
             _project = project;
             _engineConfig = engineConfig;
diff --git a/main/src/com/google/refine/sorting/BaseSorter.java b/main/src/com/google/refine/sorting/BaseSorter.java
index 1f5346d9d..67fa23f1a 100644
--- a/main/src/com/google/refine/sorting/BaseSorter.java
+++ b/main/src/com/google/refine/sorting/BaseSorter.java
@@ -35,8 +35,6 @@ package com.google.refine.sorting;
 
 import java.util.List;
 
-import org.json.JSONException;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.model.Project;
 import com.google.refine.sorting.Criterion.KeyMaker;
@@ -102,7 +100,7 @@ abstract public class BaseSorter {
         }
     }
 
-    public void initializeFromConfig(Project project, SortingConfig config) throws JSONException {
+    public void initializeFromConfig(Project project, SortingConfig config) {
         _criteria = config.getCriteria();
         int count = _criteria.length;
         _keyMakers = new KeyMaker[count];