Index: Core/Common/src/Core.Common.Base/ObservableUniqueItemCollectionWithSourcePath.cs
===================================================================
diff -u -r121f0e24e6f6550f84a564228865287a87ad9e87 -rb0af1f0a52601b8e6b519f9b59d5c5a30ff19b2a
--- Core/Common/src/Core.Common.Base/ObservableUniqueItemCollectionWithSourcePath.cs	(.../ObservableUniqueItemCollectionWithSourcePath.cs)	(revision 121f0e24e6f6550f84a564228865287a87ad9e87)
+++ Core/Common/src/Core.Common.Base/ObservableUniqueItemCollectionWithSourcePath.cs	(.../ObservableUniqueItemCollectionWithSourcePath.cs)	(revision b0af1f0a52601b8e6b519f9b59d5c5a30ff19b2a)
@@ -146,7 +146,7 @@
             {
                 throw new ArgumentNullException(nameof(filePath));
             }
-            if (!IOUtils.IsValidFilePath(filePath))
+            if (!IOUtils.IsValidFilePath(filePath) && filePath.Length > 0)
             {
                 throw new ArgumentException($"'{filePath}' is not a valid file path.", nameof(filePath));
             }
Index: Core/Common/test/Core.Common.Base.Test/ObservableUniqueItemCollectionWithSourcePathTest.cs
===================================================================
diff -u -r67284323e2785c651633d9c52049ba12a9c70e6a -rb0af1f0a52601b8e6b519f9b59d5c5a30ff19b2a
--- Core/Common/test/Core.Common.Base.Test/ObservableUniqueItemCollectionWithSourcePathTest.cs	(.../ObservableUniqueItemCollectionWithSourcePathTest.cs)	(revision 67284323e2785c651633d9c52049ba12a9c70e6a)
+++ Core/Common/test/Core.Common.Base.Test/ObservableUniqueItemCollectionWithSourcePathTest.cs	(.../ObservableUniqueItemCollectionWithSourcePathTest.cs)	(revision b0af1f0a52601b8e6b519f9b59d5c5a30ff19b2a)
@@ -155,6 +155,26 @@
         }
 
         [Test]
+        public void AddRange_AddNewItemForEmptyPath_CollectionContainsItem()
+        {
+            // Setup
+            var collection = new ConcreteObservableUniqueItemCollectionWithSourcePath<TestItem>(
+                getUniqueFeature, typeDescriptor, featureDescription);
+            var item = new TestItem("Item A");
+
+            // Call 
+            const string filePath = "";
+            collection.AddRange(new[]
+            {
+                item
+            }, filePath);
+
+            // Assert
+            CollectionAssert.Contains(collection, item);
+            Assert.AreEqual(filePath, collection.SourcePath);
+        }
+
+        [Test]
         public void AddRange_AddNewItem_CollectionContainsItem()
         {
             // Setup