From v 1.5 version onwards, you'll not worry anymore if you would have outdated version of the software. AfterMath, a member of a developer team of Mission Maker posted this on Discord, which showcased new "auto-update" software that will be implemented. It will search through the MM versions database and notifiy you, if there would be a new version for download - if yes, it will be automatically downloaded & installed.
Still there are no more news regarding Mission Maker v 1.5 however there's one interesting screenshot, that Naloger posted. He said: You will be able to choose the skin for the appearance of the mission
Take a look:
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