diff --git a/README.md b/README.md
index 06f9f11..d19d104 100644
--- a/README.md
+++ b/README.md
@@ -376,6 +376,7 @@ If you want to contribute, please check out our [Code of Conduct](https://github
 |initializeHydraulicAnalysis|Initializes storage tank levels, link status and settings, and the simulation clock time prior to running a hydraulic analysis
 |initializeQualityAnalysis|Initializes water quality and the simulation clock time prior to running a water quality analysis
 |loadEPANETFile|Load epanet file when use bin functions
+|loadMSXEPANETFile|Re-Load EPANET MSX file - parfor
 |nextHydraulicAnalysisStep|Determines the length of time until the next hydraulic event occurs in an extended period simulation
 |nextQualityAnalysisStep|Advances the water quality simulation to the start of the next hydraulic time period
 |openAnyInp|Open as on matlab editor any EPANET input file using built function open
diff --git a/epyt/epanet.py b/epyt/epanet.py
index 3283446..cdb557c 100644
--- a/epyt/epanet.py
+++ b/epyt/epanet.py
@@ -516,7 +516,8 @@ def __init__(self, *argv, version=2.2, ph=False, loadfile=False, customlib=None,
         warnings.simplefilter('always')
         # Demand model types. DDA #0 Demand driven analysis,
         # PDA #1 Pressure driven analysis.
-        self.msxname = None
+        self.MSXFile = None
+        self.MSXTempFile = None
         self.DEMANDMODEL = ['DDA', 'PDA']
         # Link types
         self.TYPELINK = ['CVPIPE', 'PIPE', 'PUMP', 'PRV', 'PSV',
@@ -6503,8 +6504,18 @@ def loadEPANETFile(self, *argv):
         else:
             self.api.ENopen(argv[0], argv[1], argv[2])
 
+    def loadMSXEPANETFile(self, msxfile):
+        """ Load EPANET MSX file.
+
+        Example:
+
+        >>> d.loadMSXEPANETFile(d.MSXTempFile)
+        """
+        err = self.msx.msx_lib.MSXopen(c_char_p(msxfile.encode('utf-8')))
+        return err
+
     def max(self, value):
-        """ Retrieves the max value of numpy.array or numpy.mat """
+        """ Retrieves the smax value of numpy.array or numpy.mat """
         return np.max(value)
 
     def multiply_elements(self, arr1, arr2):
@@ -11243,9 +11254,10 @@ def loadMSXFile(self, msxname, customMSXlib=None, ignore_properties=False):
                     continue
                 break
 
-        self.msxname = msxname[:-4] + '_temp.msx'
-        copyfile(msxname, self.msxname)
-        self.msx = epanetmsxapi(self.msxname, customMSXlib=customMSXlib, display_msg=self.display_msg)
+        self.MSXFile = msxname[:-4]
+        self.MSXTempFile = msxname[:-4] + '_temp.msx'
+        copyfile(msxname, self.MSXTempFile)
+        self.msx = epanetmsxapi(self.MSXTempFile, customMSXlib=customMSXlib, display_msg=self.display_msg)
 
         # Message to user if he uses ph with msx
         if self.api._ph is not None:
@@ -11499,7 +11511,7 @@ def getMSXOptions(self):
             in_options = False
 
             # Open and read the file
-            with open(self.msxname, 'r') as file:
+            with open(self.MSXTempFile, 'r') as file:
                 for line in file:
                     # Check for [OPTIONS] section
                     if "[OPTIONS]" in line:
@@ -12040,7 +12052,7 @@ def getMSXSpeciesUnits(self, varagin=None):
         return value
 
     def getEquations(self):
-        msxname = self.msxname
+        msxname = self.MSXTempFile
         Terms = {}
         Pipes = {}
         Tanks = {}
@@ -12409,8 +12421,8 @@ def changeMSXOptions(self, param, change):
             f.truncate()
 
         self.msx.MSXclose()
-        copyfile(options_section, self.msxname)
-        self.msx.MSXopen(self.msxname, reload = True)
+        copyfile(options_section, self.MSXTempFile)
+        self.loadMSXEPANETFile(self.MSXTempFile)
 
     def setMSXAreaUnitsCM2(self):
         """  Sets the area units to square centimeters.
@@ -16171,7 +16183,7 @@ def __init__(self, msxfile='', loadlib=True, ignore_msxfile=False, customMSXlib=
         if not ignore_msxfile:
             self.MSXopen(msxfile)
 
-    def MSXopen(self, msxfile, reload = False):
+    def MSXopen(self, msxfile):
         """
         Open MSX file
         filename - Arsenite.msx or use full path
@@ -16183,7 +16195,7 @@ def MSXopen(self, msxfile, reload = False):
         if not os.path.exists(msxfile):
             raise FileNotFoundError(f"File not found: {msxfile}")
 
-        if self.display_msg and not reload:
+        if self.display_msg:
             print("Opening MSX file:", msxfile)
         msxbasename = os.path.basename(msxfile)
         err = self.msx_lib.MSXopen(c_char_p(msxfile.encode('utf-8')))
diff --git a/sis4_5 b/sis4_5
new file mode 100644
index 0000000..7b2fbdc
Binary files /dev/null and b/sis4_5 differ