diff --git a/src/backends/lua/luaexpression.h b/src/backends/lua/luaexpression.h
--- a/src/backends/lua/luaexpression.h
+++ b/src/backends/lua/luaexpression.h
@@ -36,6 +36,7 @@
     void evaluate();
     void interrupt();
     void parseOutput(QString& output);
+    void parseError(QString& error);
 
 };
 
diff --git a/src/backends/lua/luaexpression.cpp b/src/backends/lua/luaexpression.cpp
--- a/src/backends/lua/luaexpression.cpp
+++ b/src/backends/lua/luaexpression.cpp
@@ -58,6 +58,13 @@
         currentSession->runExpression(this);
 }
 
+void LuaExpression::parseError(QString &error)
+{
+    qDebug() << error;
+    setErrorMessage(error);
+    setStatus(Error);
+}
+
 void LuaExpression::parseOutput(QString &output)
 {
     output.replace(command(), QLatin1String(""));
diff --git a/src/backends/lua/luasession.cpp b/src/backends/lua/luasession.cpp
--- a/src/backends/lua/luasession.cpp
+++ b/src/backends/lua/luasession.cpp
@@ -108,7 +108,13 @@
 
 void LuaSession::readError()
 {
-    qDebug() << m_process->readAllStandardError() << endl;
+    qDebug() << "readError";
+    QString error = QString::fromLocal8Bit(m_process->readAllStandardError());
+    if (!m_currentExpression || error.isEmpty())
+    {
+        return;
+    }
+    m_currentExpression->parseError(error);
 }
 
 void LuaSession::processStarted()