Assert() is not working in Code::Blocks

[nikosxatz]

In code::blocks 12.11 the following code:

#include <iostream>
#include <cassert>
using namespace std;


int main()
{
int a=4;
assert(a==4);
return 0;
}

Gives the following error in the assert() Line:

In function 'int main()':|
error: converting to execution character set: Illegal byte sequence|