fix

src/Visual_DVM_2021/UI/Main/SapforVersionsComparisonForm.java

@@ -144,7 +144,7 @@ public class SapforVersionsComparisonForm extends ComparisonForm<SapforVersion_j
             if (state != null) {
                 buttons.get(state).doClick();
             }
-            return true;
+            return isReady();
         } else {
             cbFile.setSelectedIndex(-1);
             for (int i = 0; i < cbFile.getItemCount(); ++i) {