Index: trunk/Mars/mbase/MLog.cc
===================================================================
--- trunk/Mars/mbase/MLog.cc	(revision 20095)
+++ trunk/Mars/mbase/MLog.cc	(revision 20096)
@@ -99,4 +99,9 @@
 #include <iomanip>
 
+#if ROOT_VERSION_CODE >= ROOT_VERSION(6,24,00)
+#include <mutex>
+#endif
+
+
 #include <TROOT.h>      // gROOT->GetListOfCleanups()
 #include <TSystem.h>
@@ -150,4 +155,10 @@
 MLog gLog;
 
+/// Serializes error output, destructed by the gROOT destructor via ReleaseDefaultErrorHandler()
+ static std::mutex *GetErrorMutex() {
+    static std::mutex *m = new std::mutex();
+    return m;
+ }
+ 
 // --------------------------------------------------------------------------
 //
@@ -760,5 +771,9 @@
     // if abort is set it aborts the application.
    if (gErrorIgnoreLevel == kUnset) {
-      R__LOCKGUARD2(gErrorMutex);
+#if ROOT_VERSION_CODE < ROOT_VERSION(6,24,00)
+       R__LOCKGUARD2(gErrorMutex);
+#else
+       std::lock_guard<std::mutex> guard(*GetErrorMutex());
+#endif
 
       gErrorIgnoreLevel = 0;
@@ -789,5 +804,9 @@
 void MLog::ErrorHandlerPrint(Int_t level, const char *location, const char *msg)
 {
+#if ROOT_VERSION_CODE < ROOT_VERSION(6,24,00)
     R__LOCKGUARD2(gErrorMutex);
+#else
+    std::lock_guard<std::mutex> guard(*GetErrorMutex());
+#endif
 
     if (level >= kError)
Index: trunk/Mars/mcamera/MCameraDC.cc
===================================================================
--- trunk/Mars/mcamera/MCameraDC.cc	(revision 20095)
+++ trunk/Mars/mcamera/MCameraDC.cc	(revision 20096)
@@ -106,5 +106,5 @@
 Float_t MCameraDC::GetMin() const
 {
-    Float_t val = (UInt_t)-1;
+    Float_t val = std::numeric_limits<Float_t>::max();
     for (int i=0; i<fArray.GetSize(); i++)
         val = TMath::Min(val, GetCurrent(i));
Index: trunk/Mars/mhbase/MH3.cc
===================================================================
--- trunk/Mars/mhbase/MH3.cc	(revision 20095)
+++ trunk/Mars/mhbase/MH3.cc	(revision 20096)
@@ -918,11 +918,11 @@
             return kTRUE;
         case kLabelsX:
-            static_cast<TProfile2D*>(fHist)->Fill(labelx, y,      z);
+            static_cast<TProfile2D*>(fHist)->Fill(labelx, y,      z, 1.);
             return kTRUE;
         case kLabelsY:
-            static_cast<TProfile2D*>(fHist)->Fill(x,      labely, z);
+            static_cast<TProfile2D*>(fHist)->Fill(x,      labely, z, 1.);
             return kTRUE;
         case kLabelsXY:
-            static_cast<TProfile2D*>(fHist)->Fill(labelx, labely, z);
+            static_cast<TProfile2D*>(fHist)->Fill(labelx, labely, z, 1.);
             return kTRUE;
         }
Index: trunk/Mars/mhcalib/MHCalibrationChargeBlindPix.cc
===================================================================
--- trunk/Mars/mhcalib/MHCalibrationChargeBlindPix.cc	(revision 20095)
+++ trunk/Mars/mhcalib/MHCalibrationChargeBlindPix.cc	(revision 20096)
@@ -81,4 +81,5 @@
 #include <TH2D.h>
 #include <TRandom.h>
+#include <TLine.h> // root 6.24
 
 #include "MLog.h"
Index: trunk/Mars/mhflux/MHAlpha.cc
===================================================================
--- trunk/Mars/mhflux/MHAlpha.cc	(revision 20095)
+++ trunk/Mars/mhflux/MHAlpha.cc	(revision 20096)
@@ -50,4 +50,5 @@
 #include <TCanvas.h>
 #include <TPaveStats.h>
+#include <TLine.h> // root 6.24
 
 #include "MHillas.h"
Index: trunk/Mars/mhflux/MHFalseSource.cc
===================================================================
--- trunk/Mars/mhflux/MHFalseSource.cc	(revision 20095)
+++ trunk/Mars/mhflux/MHFalseSource.cc	(revision 20096)
@@ -127,4 +127,5 @@
 #include <TPaveText.h>
 #include <TStopwatch.h>
+#include <TLine.h> // root 6.24
 
 #include "MGeomCam.h"