diff --git a/src/plugins/kumircoderun/run.cpp b/src/plugins/kumircoderun/run.cpp
index 8a88e8f9332801bf902185d4bb3d5d7b6d78714c..3bf6c920fe354730aef20dc85378b1fe8aa0f15b 100644
--- a/src/plugins/kumircoderun/run.cpp
+++ b/src/plugins/kumircoderun/run.cpp
@@ -218,6 +218,8 @@ bool Run::makeInputArgument(Variable & reference)
 }
 
 bool Run::makeOutputArgument(const Variable & reference) {
+    if (!reference.isValid())
+        return true;
     QString repr;
     emit output(QString::fromStdWString(reference.name())+" = ");
     if (reference.dimension()==0) {
diff --git a/src/shared/vm/vm.hpp b/src/shared/vm/vm.hpp
index 51b6e3052b1a9efb539640a17a030171b92b6d44..87b24dd888b4b8645f57a1da56361d6154789266 100644
--- a/src/shared/vm/vm.hpp
+++ b/src/shared/vm/vm.hpp
@@ -2048,6 +2048,8 @@ void KumirVM::do_store(uint8_t s, uint16_t id)
         if (m_externalHandler)
             m_externalHandler->noticeOnValueChange(lineNo, qn);
     }
+    if (stack_contexts.top().type==Bytecode::EL_BELOWMAIN)
+        Variable::unsetError();
     s_error = Kumir::Core::getError();
     nextIP();
     if (m_dontTouchMe) m_dontTouchMe->unlock();
diff --git a/src/tools/run/main.cpp b/src/tools/run/main.cpp
index f3ed0e05a23660c191e65845c1486a91e4ed0d01..a3d73bd5093d596e1cc59aa1cdb41f0723762f93 100644
--- a/src/tools/run/main.cpp
+++ b/src/tools/run/main.cpp
@@ -226,6 +226,8 @@ bool InteractionHandler::makeInputArgument(VM::Variable &reference)
 }
 
 bool InteractionHandler::makeOutputArgument(const VM::Variable & reference) {
+    if (!reference.isValid())
+        return true;
     Kumir::String repr;
     output(reference.name()+Kumir::Core::fromAscii(" = "));
     if (reference.dimension()==0) {