diff -r 80b319c1f0d0 main/MainWindow.cpp
--- a/main/MainWindow.cpp	Thu Nov 21 14:22:38 2019 +0000
+++ b/main/MainWindow.cpp	Fri Nov 22 11:07:06 2019 +0000
@@ -54,10 +54,13 @@
 #include "data/fileio/CSVFormat.h"
 #include "data/fileio/CSVFileWriter.h"
 #include "data/fileio/MIDIFileWriter.h"
+#include "data/fileio/AudioFileReaderFactory.h"
 #include "rdf/RDFExporter.h"
 
 #include "widgets/RangeInputDialog.h"
 #include "widgets/ActivityLog.h"
+#include "widgets/InteractiveFileFinder.h"
+#include "widgets/ProgressDialog.h"
 
 // For version information
 #include "vamp/vamp.h"
@@ -1761,11 +1764,28 @@
     if (orig == "") orig = ".";
     else orig = QFileInfo(orig).absoluteDir().canonicalPath();
 
-    QString path = getOpenFileName(FileFinder::AnyFile);
-
+    QString path = getOpenFileName(FileFinder::SessionOrAudioFile);
     if (path.isEmpty()) return;
 
-    FileOpenStatus status = openPath(path, ReplaceSession);
+    FileSource source(path);
+
+    FileOpenStatus status = FileOpenFailed;
+    
+    if (source.isAvailable()) {
+
+        QString ext = source.getExtension().toLower();
+        
+        bool isAudio =
+            AudioFileReaderFactory::getKnownExtensions().contains(ext);
+
+        bool isSession = InteractiveFileFinder::getInstance()->
+            getApplicationSessionExtension() == ext;
+
+        if (isAudio || isSession) {
+            source.waitForData();
+            status = open(source, ReplaceSession);
+        }
+    }
 
     if (status == FileOpenFailed) {
         QMessageBox::critical(this, tr("Failed to open file"),
@@ -1790,12 +1810,33 @@
          QLineEdit::Normal, lastLocation, &ok);
 
     if (!ok) return;
+    if (text.isEmpty()) return;
 
     settings.setValue("lastremote", text);
 
-    if (text.isEmpty()) return;
-
-    FileOpenStatus status = openPath(text, ReplaceSession);
+    FileOpenStatus status = FileOpenFailed;
+
+    {
+        ProgressDialog dialog(tr("Opening file or URL..."), true, 2000, this);
+        connect(&dialog, SIGNAL(showing()), this, SIGNAL(hideSplash()));
+        FileSource source(text, &dialog);
+    
+        if (source.isAvailable()) {
+
+            QString ext = source.getExtension().toLower();
+        
+            bool isAudio =
+                AudioFileReaderFactory::getKnownExtensions().contains(ext);
+
+            bool isSession = InteractiveFileFinder::getInstance()->
+                getApplicationSessionExtension() == ext;
+
+            if (isAudio || isSession) {
+                source.waitForData();
+                status = open(source, ReplaceSession);
+            }
+        }
+    }
 
     if (status == FileOpenFailed) {
         QMessageBox::critical(this, tr("Failed to open location"),