Yesterday I installed Mycroft on my Raspberry Pi 3 B+. i got it up and running, but some of the default skills weren’t working, (most noticeably weather and time). When asked “What time is it” or “What is the weather” Mycroft would respond with “I don’t understand” or some variant of it. The relevant skills didn’t appear to be loaded, and using the :skills command on the CLI, some skills, including mycroft-weather and mycroft-date-time were red in colour. The other skills that were also not loaded included mycroft-stock, mycroft-wiki, mycroft-installer, mycroft-npr-news, mycroft-fallback-wolfram-alpha, mycroft-ip and mycroft-fallback-duck-duck-go.
I was able to fix this issue by entering the virtual environment console, and using msm remove package and msm install package for each one.
It’s a pretty straightforward fix, but I wasn’t able to find a solution online, so I’m leaving this as a reference in case it helps someone.