UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36

Steps to reproduce the problem:
1. Chromium Updater
2. I have 55.0.2883.87
3. Error message Your Chromium is out of date

What is the expected behavior?
Auto update after download

What went wrong?
I have downloaded Chromium_OSX_55.0.2883.95.dmg but nothing else is happening? The updater is still giving me the error message. I tried changing the Software Source Mirrors but that hasn't helped.

Did this work before? N/A 

Chrome version: 55.0.2883.87  Channel: stable
OS Version: Mint
Flash Version: Shockwave Flash 24.0 r0

Help!