Compiler/TMS320F28377D: Array Error

Tool/software: TI C/C++ Compiler

I am getting a #138 expression must be a modifiable lvalue  error. I have pared it down to this code snippet. I suspect I will be a little embarrassed when I find out what the problem is.

All of the Populate Array statements have this error. i am using CCS 9.3.0.00012 with compiler TI v20.2.1.LTS

Thanks for you patience and help.

// Declare Array
float   Data1_Dat   [5][5];


int main(void)
{
    // Define array
    float Data1_Dat[0][0];

    //Populate array
    Data1_Dat[0,0]  =   1.0;
    Data1_Dat[1,1]  =   2.0;
    Data1_Dat[2,2]  =   3.0;
    Data1_Dat[3,3]  =   4.0;
    Data1_Dat[4.4]  =   5.0;

    return 0;
}