Not selecting a library throws an unhandled exception and causes Kryptos to crash. Reproducing bug:
1) Launch Kryptos
2) Skip setting the library
3) Status: receiver
4) Operation: Encrypt
5) Set algorithm: DES
6) Key: Generate random key
7) Mode: ECB
8) Input, select existing file to encrypt, create new output
9) GO!
10) Unhandled Exception
Selecting a library solves the issue and Kryptos does not crash.
See screenshot attached
Crash screenshot