I have a third-party DLL (unmanaged) for which I am trying to call a
function. The function requires a structure (as an argument) which
utilized several variables I am unable to translate.

The original C header structures contain (amongst other things that I
have already translated):

typedef byte   TPacketType[int(100)];

struct TModuleRec
{
/*1 byte*/   bool      Succeeded;           
/*4 bytes*/  char      *Error;   
/*4 bytes*/  char      *ProjectFiles[7];       
/*4 bytes*/  int        ProjectFilesStart[7];
            byte       EEPROM[50];
             TPacketType  PacketBuffer;
}

I've been able to translate everything so far except for these
particular variables. I've tried (as suggested on some interop articles
I've read)

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> Public
Class TPacketType
    Public TPacketType(100) As Byte
End Class

<StructLayout(LayoutKind.Sequential)> Public Class TModuleRec
    <MarshalAs(UnmanagedType.U1)> Public Succeeded As Boolean
    Public Err(4) As Byte
    Public ProjectFiles(7) As Byte
    Public ProjectFilesStart(7) As Integer
    Dim EEPROM(50) As Byte
    Public EEPROMFlags(50) As Byte
    Public PacketBuffer As TPacketType
End Class

for the booleans, but this still results in "non-primitive or
non-blittable" structure errors (I remarked out the unmarshalled Bools
during testing).

I'd really like to understand why the MarshalAs isn't working (as well
as how to translate the other lines). Can someone offer some suggestions?