diff --git a/lib/dtscmeta.cpp b/lib/dtscmeta.cpp
index b0191fbd..f391da7b 100644
--- a/lib/dtscmeta.cpp
+++ b/lib/dtscmeta.cpp
@@ -2081,7 +2081,9 @@ namespace DTSC {
   bool Meta::toFile(const std::string & fileName){
     std::ofstream oFile(fileName.c_str());
     oFile << toJSON().toNetPacked();
+    if (!oFile.good()){return false;}
     oFile.close();
+    return true;
   }
 
   ///\brief Converts a meta object to a human readable string
diff --git a/lib/shared_memory.cpp b/lib/shared_memory.cpp
index 2752b1c5..a8afe767 100644
--- a/lib/shared_memory.cpp
+++ b/lib/shared_memory.cpp
@@ -223,6 +223,7 @@ namespace IPC {
 
   ///\brief Tries to wait for the semaphore, returns true if successful, false otherwise
   bool semaphore::tryWait() {
+    if (!(*this)){return false;}
     int result;
 #if defined(__CYGWIN__) || defined(_WIN32)
     result = WaitForSingleObject(mySem, 0);//wait at most 1ms
@@ -238,6 +239,7 @@ namespace IPC {
 
   ///\brief Tries to wait for the semaphore for a single second, returns true if successful, false otherwise
   bool semaphore::tryWaitOneSecond() {
+    if (!(*this)){return false;}
     int result;
 #if defined(__CYGWIN__) || defined(_WIN32)
     result = WaitForSingleObject(mySem, 1000);//wait at most 1s
diff --git a/src/input/input.cpp b/src/input/input.cpp
index 8227ae55..982b858c 100644
--- a/src/input/input.cpp
+++ b/src/input/input.cpp
@@ -341,6 +341,10 @@ namespace Mist {
   void Input::stream(){
     IPC::semaphore pullLock;
     pullLock.open(std::string("/MstPull_" + streamName).c_str(), O_CREAT | O_RDWR, ACCESSPERMS, 1);
+    if (!pullLock){
+      FAIL_MSG("Could not open pull lock for stream '%s' - aborting!", streamName.c_str());
+      return;
+    }
     if (!pullLock.tryWait()){
       WARN_MSG("A pull process for stream %s is already running", streamName.c_str());
       pullLock.close();