Python MITMPROXY Script with AES.MODE_ECB, supporting JSON, Need Help fixing (Script Mostly wrote)

Hello, I have a script that I had others help me with, but im having issues getting it to work and I think it might be something simple, like Padding on the AES or something else small.... The Project is: Fix or re-write / create a script to, but not limited to; Intercept AES Web Traffic, decrypt it via AES.MODE_ECB with Key as variable, eg. key='3tg0Iszj' Edit the traffic via regex, then encrypt it back with same key. (Traffic comes in JSON format) This will use mitmproxy with a python script, i have most of it complete, just cant get it to work, so need help touching it up. This will require some debugging and/or remote sharing. I had it close to working, but didn't seem to do padding correct. so the Server kicked it back. (Someone edited it a little after this and can't even get back to this point, by myself) I can give access to the Ubuntu server running the script I have and you can edit it as needed, while i push the request needed to test and make sure i get back the correct results. Im using Ubuntu 16.04 Python 2.7 (Willing to change to 3.x) Mitmproxy 0.16 [login to view URL] (Willing to upgrade to latest; v0.18.2) If you know what you are doing, we should be able to do this quick. Thanks