Thank you for posting on this. I will reach out and send you an update.
There is an issue with the internal update check. When MMM checks for an update it makes a web request to www.turnssoft.com to check that you are connected to the internet. Turnssoft.com is hosted externally and the hosting provider is having latency issues to there servers. With these latency issues MMM is failing to succeed in the web request. This latency is effecting all versions of MMM.
I was hoping that the service provider would be timely in rectifying the issue however it's been several days now.
I will be releasing a small update (6.7.1) shortly that fixes this issue internally.