diff --git a/libretroshare/src/gxs/rsgenexchange.cc b/libretroshare/src/gxs/rsgenexchange.cc
index 0a9db1e58..da8973eb1 100644
--- a/libretroshare/src/gxs/rsgenexchange.cc
+++ b/libretroshare/src/gxs/rsgenexchange.cc
@@ -322,12 +322,12 @@ void RsGenExchange::tick()
 			{
 				mIntegrityCheck = new RsGxsIntegrityCheck( mDataStore, this,
 				                                           *mSerialiser, mGixs);
-				mIntegrityCheck->start("gxs integrity");
-				mChecking = true;
+				std::string thisName = typeid(*this).name();
+				mChecking = mIntegrityCheck->start("gxs IC4 "+thisName);
 			}
 		}
 
-		if(mIntegrityCheck->isDone())
+		if(mIntegrityCheck->isDone() || !mChecking)
 		{
             std::vector<RsGxsGroupId> grpIds;
             GxsMsgReq msgIds;
diff --git a/libretroshare/src/util/rsthreads.cc b/libretroshare/src/util/rsthreads.cc
index 035ad214a..85f96b69a 100644
--- a/libretroshare/src/util/rsthreads.cc
+++ b/libretroshare/src/util/rsthreads.cc
@@ -92,11 +92,11 @@ void RsThread::resetTid()
 #ifdef WINDOWS_SYS
 	memset (&mTid, 0, sizeof(mTid));
 #else
-	mTid = 0;
+	mTid = pthread_t(); //Thread identifiers should be considered opaque and can be null.
 #endif
 }
 
-RsThread::RsThread() : mHasStopped(true), mShouldStop(false), mLastTid()
+RsThread::RsThread() : mInitMtx("RsThread"), mHasStopped(true), mShouldStop(false), mLastTid()
 #ifdef RS_THREAD_FORCE_STOP
   , mStopTimeout(0)
 #endif
@@ -115,6 +115,7 @@ void RsThread::askForStop()
 
 void RsThread::wrapRun()
 {
+	{RS_STACK_MUTEX(mInitMtx);} // Waiting Init done.
 	run();
 	resetTid();
 	mHasStopped = true;
@@ -184,6 +185,8 @@ bool RsThread::start(const std::string& threadName)
 	// Atomically check if the thread was already started and set it as running
 	if(mHasStopped.exchange(false))
 	{
+		RS_STACK_MUTEX(mInitMtx); // Block thread starting to run
+
 		mShouldStop = false;
 		int pError = pthread_create(
 		            &mTid, nullptr, &rsthread_init, static_cast<void*>(this) );
@@ -196,15 +199,6 @@ bool RsThread::start(const std::string& threadName)
 			print_stacktrace();
 			return false;
 		}
-		if(!mTid)
-		{
-			RsErr() << __PRETTY_FUNCTION__ << " pthread_create could not create"
-			        << " new thread: " << threadName << " mTid: " << mTid
-			        << std::endl;
-			mHasStopped = true;
-			print_stacktrace();
-			return false;
-		}
 
 		/* Store an extra copy of thread id for debugging */
 		mLastTid = mTid;
diff --git a/libretroshare/src/util/rsthreads.h b/libretroshare/src/util/rsthreads.h
index 82221ebbb..c33a608a8 100644
--- a/libretroshare/src/util/rsthreads.h
+++ b/libretroshare/src/util/rsthreads.h
@@ -261,6 +261,9 @@ private:
 	/** Call @see run() setting the appropriate flags around it*/
 	void wrapRun();
 
+	// To be sure Init (pthread_setname_np) is done before continue thread. Else can finish before and crash.
+	RsMutex mInitMtx;
+
 	/// True if thread is stopped, false otherwise
 	std::atomic<bool> mHasStopped;