# Zymkey AssertionError: bad return code -16

**URL:** <https://community.zymbit.com/t/zymkey-assertionerror-bad-return-code-16/615>\
**Category:** ZYMKEY4\
**Created:** [August 7, 2019, 4:56am UTC](https://community.zymbit.com/t/zymkey-assertionerror-bad-return-code-16/615 "2019-08-07T04:56:51Z")\
**Posts on this page:** 1\
**Showing post:** 1

<div class="post-metadata">

**Author:** ![sammy1997](https://yyz1.discourse-cdn.com/flex027/user_avatar/community.zymbit.com/sammy1997/32/346_2.png) [@sammy1997](https://community.zymbit.com/u/sammy1997)\
**Post date:** [August 7, 2019, 4:56am UTC](https://community.zymbit.com/t/zymkey-assertionerror-bad-return-code-16/615/1 "2019-08-07T04:56:51Z")

</div>

I had setup ZymBit with RasPi running Jessie. I was using the zymkey library to extract the key and it was working fine. To install some packages on the RasPi, I had to do a sudo apt-get update and upgrade. The binding still seems to hold as I am able to access the RasPi file system, but the python code to extract the key is giving an error - “AssertionError: bad return code -16”  
The error message being generated is:

File “”, line 1, in   
File “/usr/local/lib/python2.7/dist-packages/zymkey/module.py”, line 62, in **init**  
raise AssertionError(‘bad return code {!r}’.format(ret))  
AssertionError: bad return code -16

However, the C library still works. This problem is only with the python library

---

_[View the full topic](https://community.zymbit.com/t/zymkey-assertionerror-bad-return-code-16/615)._