diff --git a/src/base/http/requestparser.cpp b/src/base/http/requestparser.cpp
index 6067cbaa0..69d2a2cdc 100644
--- a/src/base/http/requestparser.cpp
+++ b/src/base/http/requestparser.cpp
@@ -203,7 +203,10 @@ bool RequestParser::parsePostMessage(const QByteArray &data)
 
     // application/x-www-form-urlencoded
     if (contentTypeLower.startsWith(CONTENT_TYPE_FORM_ENCODED)) {
-        QListIterator<QStringPair> i(QUrlQuery(data).queryItems(QUrl::FullyDecoded));
+        // [URL Standard] 5.1 application/x-www-form-urlencoded parsing
+        const QByteArray processedData = QByteArray(data).replace('+', ' ');
+
+        QListIterator<QStringPair> i(QUrlQuery(processedData).queryItems(QUrl::FullyDecoded));
         while (i.hasNext()) {
             const QStringPair pair = i.next();
             m_request.posts[pair.first] = pair.second;
diff --git a/src/webui/api/synccontroller.cpp b/src/webui/api/synccontroller.cpp
index 0bc77fd14..e16e059b2 100644
--- a/src/webui/api/synccontroller.cpp
+++ b/src/webui/api/synccontroller.cpp
@@ -29,8 +29,8 @@
 #include "synccontroller.h"
 
 #include <QJsonObject>
+#include <QMetaObject>
 #include <QThread>
-#include <QTimer>
 
 #include "base/bittorrent/peerinfo.h"
 #include "base/bittorrent/session.h"
@@ -330,7 +330,7 @@ SyncController::SyncController(ISessionManager *sessionManager, QObject *parent)
     connect(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::checked, this, &SyncController::freeDiskSpaceSizeUpdated);
 
     m_freeDiskSpaceThread->start();
-    QTimer::singleShot(0, m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::check);
+    invokeChecker();
     m_freeDiskSpaceElapsedTimer.start();
 }
 
@@ -516,7 +516,7 @@ void SyncController::torrentPeersAction()
 qint64 SyncController::getFreeDiskSpace()
 {
     if (m_freeDiskSpaceElapsedTimer.hasExpired(FREEDISKSPACE_CHECK_TIMEOUT)) {
-        QTimer::singleShot(0, m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::check);
+        invokeChecker();
         m_freeDiskSpaceElapsedTimer.restart();
     }
 
@@ -527,3 +527,12 @@ void SyncController::freeDiskSpaceSizeUpdated(qint64 freeSpaceSize)
 {
     m_freeDiskSpace = freeSpaceSize;
 }
+
+void SyncController::invokeChecker() const
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 10, 0))
+    QMetaObject::invokeMethod(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::check, Qt::QueuedConnection);
+#else
+    QMetaObject::invokeMethod(m_freeDiskSpaceChecker, "check", Qt::QueuedConnection);
+#endif
+}
diff --git a/src/webui/api/synccontroller.h b/src/webui/api/synccontroller.h
index e6c48c669..35422478a 100644
--- a/src/webui/api/synccontroller.h
+++ b/src/webui/api/synccontroller.h
@@ -56,6 +56,7 @@ private slots:
 
 private:
     qint64 getFreeDiskSpace();
+    void invokeChecker() const;
 
     qint64 m_freeDiskSpace = 0;
     FreeDiskSpaceChecker *m_freeDiskSpaceChecker = nullptr;