diff --git a/PRIVATE b/PRIVATE
index ae5882a2f..4c9a47e76 160000
--- a/PRIVATE
+++ b/PRIVATE
@@ -1 +1 @@
-Subproject commit ae5882a2ffd932807d7589bc375ebff01836495f
+Subproject commit 4c9a47e76ca23cbae70d47b2ab07d1ec15e158d7
diff --git a/examples/FEM/polyXtal/material.yaml b/examples/FEM/polyXtal/material.yaml
index 3d4b0addf..5c00f17ad 100644
--- a/examples/FEM/polyXtal/material.yaml
+++ b/examples/FEM/polyXtal/material.yaml
@@ -1,5 +1,6 @@
 homogenization:
   SX:
+    N_constituents: 1
     mech: {type: none}
 
 phase:
diff --git a/examples/SpectralMethod/Polycrystal/material.yaml b/examples/SpectralMethod/Polycrystal/material.yaml
index 394d16ed8..cdc210152 100644
--- a/examples/SpectralMethod/Polycrystal/material.yaml
+++ b/examples/SpectralMethod/Polycrystal/material.yaml
@@ -1,5 +1,6 @@
 homogenization:
   SX:
+    N_constituents: 1
     mech: {type: none}
 
 material:
diff --git a/src/IO.f90 b/src/IO.f90
index 4a442cb06..a95938a7f 100644
--- a/src/IO.f90
+++ b/src/IO.f90
@@ -371,8 +371,6 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
       msg = 'write error for file:'
     case (102)
       msg = 'could not read file:'
-    case (103)
-      msg = 'could not assemble input files'
     case (106)
       msg = 'working directory does not exist:'
 
@@ -411,7 +409,7 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
       msg = 'not enough interaction parameters given'
 
 !--------------------------------------------------------------------------------------------------
-! errors related to the parsing of material.config
+! errors related to the parsing of material.yaml
     case (140)
       msg = 'key not found'
     case (141)
diff --git a/src/homogenization_mech_RGC.f90 b/src/homogenization_mech_RGC.f90
index 6c015eea8..b429e949f 100644
--- a/src/homogenization_mech_RGC.f90
+++ b/src/homogenization_mech_RGC.f90
@@ -165,7 +165,7 @@ module subroutine mech_RGC_init(num_homogMech)
 
     prm%N_constituents = homogMech%get_asInts('cluster_size',requiredSize=3)
     if (homogenization_Ngrains(h) /= product(prm%N_constituents)) &
-      call IO_error(211,ext_msg='clustersize (mech_rgc)')
+      call IO_error(211,ext_msg='N_constituents (mech_RGC)')
 
     prm%xi_alpha = homogMech%get_asFloat('xi_alpha')
     prm%c_alpha  = homogMech%get_asFloat('c_alpha')
diff --git a/src/homogenization_mech_isostrain.f90 b/src/homogenization_mech_isostrain.f90
index 5eec454f1..f064578c8 100644
--- a/src/homogenization_mech_isostrain.f90
+++ b/src/homogenization_mech_isostrain.f90
@@ -51,7 +51,7 @@ module subroutine mech_isostrain_init
     homogMech => homog%get('mech')
     associate(prm => param(homogenization_typeInstance(h)))
 
-    prm%N_constituents = homog%get_asInt('N_constituents')
+    prm%N_constituents = homogenization_Ngrains(h)
     select case(homogMech%get_asString('mapping',defaultVal = 'sum'))
       case ('sum')
         prm%mapping = parallel_ID
diff --git a/src/homogenization_mech_none.f90 b/src/homogenization_mech_none.f90
index 3cbec5911..a58147c45 100644
--- a/src/homogenization_mech_none.f90
+++ b/src/homogenization_mech_none.f90
@@ -24,8 +24,11 @@ module subroutine mech_none_init
   print'(a,i2)', ' # instances: ',Ninstance; flush(IO_STDOUT)
 
   do h = 1, size(homogenization_type)
-    if (homogenization_type(h) /= HOMOGENIZATION_NONE_ID) cycle
+    if(homogenization_type(h) /= HOMOGENIZATION_NONE_ID) cycle
 
+    if(homogenization_Ngrains(h) /= 1) &
+      call IO_error(211,ext_msg='N_constituents (mech_none)')
+    
     NofMyHomog = count(material_homogenizationAt == h)
     homogState(h)%sizeState = 0
     allocate(homogState(h)%state0   (0,NofMyHomog))
diff --git a/src/material.f90 b/src/material.f90
index bab2f7499..11dfeb42e 100644
--- a/src/material.f90
+++ b/src/material.f90
@@ -256,16 +256,14 @@ subroutine material_parseHomogenization
   do h=1, material_Nhomogenization
     homog => material_homogenization%get(h)
     homogMech => homog%get('mech')
+    homogenization_Ngrains(h) = homog%get_asInt('N_constituents')
     select case (homogMech%get_asString('type'))
       case('none')
         homogenization_type(h) = HOMOGENIZATION_NONE_ID
-        homogenization_Ngrains(h) = 1
       case('isostrain')
         homogenization_type(h) = HOMOGENIZATION_ISOSTRAIN_ID
-        homogenization_Ngrains(h) = homog%get_asInt('N_constituents')
       case('RGC')
         homogenization_type(h) = HOMOGENIZATION_RGC_ID
-        homogenization_Ngrains(h) = homog%get_asInt('N_constituents')
       case default
         call IO_error(500,ext_msg=homogMech%get_asString('type'))
     end select