We are pleased to announce the release of CubeCart 6.1.5 which is available now. This is a maintenance release fixing a number of bugs further increasing stability.
We recommend navigating to Advanced > Maintenance then viewing the "Database" tab to look for any missing or incorrect indexes after your store has been upgraded to 6.1.5. Missing or incorrect database indexes can cause quite significant performance issues. Please use a tool such as phpMyAdmin to make any required changes or raise a ticket with our technical support department for official assistance.