Require Security Patch SUPEE-10266 to be installed. Any fuz, issues to be checked. Magento 188.8.131.52 Store Version. All testing to be completed on the development site.
Also check against any known issues: [url removed, login to view]
Had previously installed via ssh. Was forced to roll back update due to following issues.
1. logged in users at checkout.
2. Customer area would redirect back loop to the login screen.
3. Possible other issues not aware of.