During a training last week we have discovered a bug on windows 7 devices (3 attendees had win7, all had same issue)...

For light development when you want to overwrite file from filesystem, for example /<light-modules>/mtk/template/components/textImage.yaml, so when you create this path and also file then you figure out a typo in path ('template' instead of 'template*s*'), so will rename that folder to right name but then Magnolia stops observe this file until you restart it... last message in log is still with registered definition for wrong path and even with edits in file itself or changing path again, nothing will trigger observing of that definition again.

Just restart helps.