Thank you!

The problem is an out-of-range-problem in writing in the arrays.

for(int s = half; s < encryptArr.length; s++){
    second[s] = encryptArr[s];
  }

s is to high for second! s is only suitable for encryptArr.

Same here:

for(int j = 0; j < (encryptedText.length() / 2) + 1; j++){
      decrypted += second[j] + first[j];
    }

j at the kast step is too high for "first".

@SteffenVogel_79 any idea what is going on here?

I said post your code and not your error message... ;-)

@SteffenVogel_79 any word on this error? Could it be something in the kata?

Ahhhhm, look above. This was a snippet from your code, that you posted!

I don't know how that "+1" ended up there. My code doesn't have that and it still gives me an out of range error (over here, not on shell or IDLE).
Also, I'm a noob so a quick glance at text editing in comments would be helpful xD.

Maybe post your code here (mark as spoiler) and we will see... :-)

@guestl:
How could you solve it, if you are not clear how to do this?

Encryption: right.
Decryption: Do the encryption step by step backwards. So your second attempt is the right direction. For understanding the size of parts look at an example to encrypt a text with odd length.

I'm getting an unknown error. The only feedback I get from running the example tests is the number 8. I'm doing the Java kata. The error occurs during the testing of the decrypt function. My code passes the encrypt and null/empty tests. Any help would be greatly appreciated.