We do not support sprout privkeys that have prefix SK

src/mainwindow.cpp

@@ -931,7 +931,7 @@ void MainWindow::doImport(QList<QString>* keys) {
     keys->pop_front();
     //bool rescan = keys->isEmpty();
 
-    if (key.startsWith("SK") || key.startsWith("secret")) {
+    if (key.startsWith("secret")) {
         rpc->importZPrivKey(key, [=] (auto) { this->doImport(keys); });
     } else if (key.startsWith("U") || key.startsWith("5") || key.startsWith("L") || key.startsWith("K")) {
         // 5 = uncompressed, len=51