fixed vst loading bug

effects/internal/dropshadoweffect.cpp

@@ -0,0 +1,5 @@
+#include "dropshadoweffect.h"
+
+DropShadowEffect::DropShadowEffect() {
+
+}

effects/internal/dropshadoweffect.h

@@ -0,0 +1,11 @@
+#ifndef DROPSHADOWEFFECT_H
+#define DROPSHADOWEFFECT_H
+
+
+class DropShadowEffect
+{
+public:
+  DropShadowEffect();
+};
+
+#endif // DROPSHADOWEFFECT_H

effects/internal/vsthost.cpp

@@ -108,6 +108,10 @@ typedef void (*processFuncPtr)(AEffect *effect, float **inputs, float **outputs,
 void VSTHost::loadPlugin() {
 	QString dll_fn = file_field->get_filename(0, true);
 
+  if (dll_fn.isEmpty()) {
+    return;
+  }
+
 #if defined(__APPLE__)
 	bundle = BundleLoad(dll_fn);