diff -urN kwin-5.21.4.orig/plugins/screencast/screencastmanager.cpp kwin-5.21.4/plugins/screencast/screencastmanager.cpp
--- kwin-5.21.4.orig/plugins/screencast/screencastmanager.cpp	2021-04-06 15:27:01.000000000 +0300
+++ kwin-5.21.4/plugins/screencast/screencastmanager.cpp	2021-04-19 10:58:00.395022083 +0300
@@ -131,7 +131,7 @@
     connect(waylandStream, &KWaylandServer::ScreencastStreamV1Interface::finished, stream, &PipeWireStream::stop);
     connect(stream, &PipeWireStream::stopStreaming, waylandStream, [stream, waylandStream] {
         waylandStream->sendClosed();
-        delete stream;
+        stream->deleteLater();
     });
     connect(stream, &PipeWireStream::streamReady, stream, [waylandStream] (uint nodeid) {
         waylandStream->sendCreated(nodeid);