Error:Could not load type from assembly Culture=neutral, PublicKeyToken=null' because it contains an object field at offset 75 that is incorrectly aligned or overlapped by a non-object field.

Question

I got an error while I creating a structure.
[FieldOffset(72)]
[MarshalAs(UnmanagedType.ByValArray,SizeConst= 3)]
public int[] DC;
[FieldOffset(75)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
public float[] WIN;
[FieldOffset(83)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
public byte[] name;
[FieldOffset(103)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
public byte[] SET;
[FieldOffset(106)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 50)]
public byte[] ID;
Error as like this-->object field at offset 75 that is incorrectly aligned or overlapped by a non-object field. But here size constant is 3 so I think after 72 offset will be 75..If I change the offset to 76 it will works fine. I think reason is that
size of int is 4. After changing that code will be like this.
[FieldOffset(72)]
[MarshalAs(UnmanagedType.ByValArray,SizeConst= 3)]
public int[] DC;
[FieldOffset(76)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
public float[] WIN;
[FieldOffset(84)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
public byte[] name;
[FieldOffset(104)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
public byte[] SET;
[FieldOffset(107)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 50)]
public byte[] ID;
But at that time I got the  error as object field at offset 107 that is incorrectly aligned or overlapped by a non-object field..Can anyone tell me what is the main reason behind this..
Thanks..

Answer 1

Hi,
Please firstly take a look at this documentation:
MarshalAsAttribute.SizeConst Field
Indicates the number of   elements in the fixed-length array or the number of characters (not bytes) in   a string to import
Change your code like this should work:
[FieldOffset(72)]
[MarshalAs(UnmanagedType.ByValArray,SizeConst= 3)]
public int[] DC;
[FieldOffset(84)]//72+4*3
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
public float[] WIN;
[FieldOffset(116)]//84+4*8
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 20)]
public byte[] name;
[FieldOffset(136)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
public byte[] SET;
[FieldOffset(139)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 50)]
public byte[] ID;
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