FPE encryption of words

#include <botan/fpe_fe1.h>
#include <assert.h>
#include <iostream>

using namespace Botan;

BigInt power(size_t g, size_t x)
   {
   BigInt r = 1;
   for(size_t i = 0; i != x; ++i)
      r *= g;
   return r;
   }

BigInt rank(const std::string& s)
   {
   BigInt r = 0;
   for(size_t i = 0; i != s.size(); ++i)
      {
      char c = s[i];
      if(::islower(c) == false)
         throw std::runtime_error("Unexpected character in string");

      r *= 26;
      r += (c - 'a');
      }

   return r;
   }

std::string derank(BigInt n, size_t len)
   {
   std::string s;

   for(size_t i = 0; i != len; ++i)
      {
      char c = 'a' + (n % 26);
      s.push_back(c);
      n /= 26;
      }

   std::reverse(s.begin(), s.end());

   return s;
   }

int main()
   {
   const SymmetricKey key("ABCDEF");

   std::vector<std::string> words = {
      "aaa", "abc", "abcc",
      "here", "are", "some", "words", "i", "will", "encrypt",
      "some", "are", "longer", "some", "are", "shorter",
      "notice", "that", "some", "is", "encrypted", "differently",
      "each", "time", "due", "to", "the", "changing", "tweak",
   };

   std::vector<uint8_t> tweak(8);
   uint64_t ctr = 0;

   for(std::string word : words)
      {
      const size_t len = word.size();

      BigInt r = rank(word);

      assert(word == derank(r, len));

      // This could be cached instead of repeatedly computed
      BigInt mod = power(26, len);

      BigInt c = FPE::fe1_encrypt(mod, r, key, tweak);
      std::string ctext = derank(c, len);

      std::cout << word << " -> "<< ctext << "\n";

      BigInt p = FPE::fe1_decrypt(mod, rank(ctext), key, tweak);
      std::string ptext = derank(p, ctext.size());

      assert(ptext == word);

      ++ctr;
      store_be(ctr, tweak.data());
      }

   }

when I run this test program it fails in line 49
const SymmetricKey key("ABCDEF");
when I run it in debug, however it doesn't.

I built it in VC2017 on windows.
is there a known issue?

botan was build in 32 bit.

never mind, somehow I got this working again for me.
may have been the configuration options.
This worked for me:
python configure.py --cpu=x86 --os=windows --cc=msvc