diff --git a/src/IO.f90 b/src/IO.f90
index d4533f47c..fd3b5bb48 100644
--- a/src/IO.f90
+++ b/src/IO.f90
@@ -484,8 +484,6 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
       msg = 'too many systems requested'
     case (146)
       msg = 'number of values does not match'
-    case (147)
-      msg = 'not supported anymore'
     case (148)
       msg = 'Nconstituents mismatch between homogenization and microstructure'
 
@@ -497,22 +495,10 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
       msg = 'microstructure has no constituents'
     case (153)
       msg = 'sum of phase fractions differs from 1'
-    case (154)
-      msg = 'homogenization index out of bounds'
     case (155)
       msg = 'microstructure index out of bounds'
-    case (157)
-      msg = 'invalid texture transformation specified'
-    case (160)
-      msg = 'no entries in config part'
-    case (161)
-      msg = 'config part found twice'
-    case (165)
-      msg = 'homogenization configuration'
-    case (170)
-      msg = 'no homogenization specified via State Variable 2'
     case (180)
-      msg = 'no microstructure specified via State Variable 3'
+      msg = 'missing/invalid microstructure definition via State Variable 2'
     case (190)
       msg = 'unknown element type:'
     case (191)
@@ -525,8 +511,6 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
     case (201)
       msg = 'unknown plasticity specified:'
 
-    case (210)
-      msg = 'unknown material parameter:'
     case (211)
       msg = 'material parameter out of bounds:'
     case (212)
@@ -534,8 +518,6 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
 
 !--------------------------------------------------------------------------------------------------
 ! numerics error messages
-    case (300)
-      msg = 'unknown numerics parameter:'
     case (301)
       msg = 'numerics parameter out of bounds:'
 
@@ -555,10 +537,6 @@ subroutine IO_error(error_ID,el,ip,g,instance,ext_msg)
 
 !--------------------------------------------------------------------------------------------------
 ! user errors
-    case (600)
-      msg = 'Ping-Pong not possible when using non-DAMASK elements'
-    case (601)
-      msg = 'Ping-Pong needed when using non-local plasticity'
     case (602)
       msg = 'invalid selection for debug'
 
diff --git a/src/marc/discretization_marc.f90 b/src/marc/discretization_marc.f90
index edf99523c..397e7514c 100644
--- a/src/marc/discretization_marc.f90
+++ b/src/marc/discretization_marc.f90
@@ -723,6 +723,8 @@ subroutine inputRead_microstructure(microstructureAt,&
     endif
   enddo
 
+  if(any(microstructureAt < 1)) call IO_error(190)
+
 end subroutine inputRead_microstructure
 
 
@@ -1061,7 +1063,7 @@ function IPneighborhood(elem,connectivity)
   integer, dimension(size(connectivity,1))  :: myConnectivity
   integer, dimension(size(elem%cellFace,1)) :: face_unordered
   integer :: e,i,f,n,c,s
- 
+
   c = 0
   do e = 1, size(connectivity,3)
     do i = 1, size(connectivity,2)
@@ -1078,9 +1080,9 @@ function IPneighborhood(elem,connectivity)
   enddo; enddo
 
 !--------------------------------------------------------------------------------------------------
-! sort face definitions 
+! sort face definitions
   call math_sort(face,sortDim=1)
-  do c=2, size(face,1)-4 
+  do c=2, size(face,1)-4
     s = 1
     e = 1
     do while (e < size(face,2))
@@ -1091,8 +1093,8 @@ function IPneighborhood(elem,connectivity)
       endif
     enddo
   enddo
- 
-  IPneighborhood = 0 
+
+  IPneighborhood = 0
   do c=1, size(face,2) - 1
     if(all(face(:n-1,c) == face(:n-1,c+1))) then
       IPneighborhood(:,face(n+2,c+1),face(n+1,c+1),face(n+0,c+1)) = face(n:n+3,c+0)