TypeError: Non-hexadecimal digit found

[AndreMiras]

https://sentry.io/andre-5t/pywallet/issues/751979004/

TypeError: Non-hexadecimal digit found
(5 additional frame(s) were not displayed)
...
  File "home/andre/workspace/PyWallet/.buildozer/android/platform/build/dists/pywallet/private/lib/python2.7/site-packages/devp2p/service.py", line 47, in register_with_app
  File "home/andre/workspace/PyWallet/.buildozer/android/platform/build/dists/pywallet/private/lib/python2.7/site-packages/pyethapp/accounts.py", line 232, in __init__
  File "home/andre/workspace/PyWallet/.buildozer/android/platform/build/dists/pywallet/private/lib/python2.7/site-packages/pyethapp/accounts.py", line 79, in load
  File "home/andre/workspace/PyWallet/.buildozer/android/platform/build/dists/pywallet/private/lib/python2.7/site-packages/pyethapp/accounts.py", line 41, in __init__
  File "home/andre/workspace/PyWallet/.buildozer/android/platform/build/dists/pywallet/private/lib/python2.7/encodings/hex_codec.py", line 42, in hex_decode

TypeError: Non-hexadecimal digit found