bdpopeye
Looks like Playlet is having some issues. It was down last week as well (failing to launch/crash), but then started working again.
Currently, mine is opening but am met with errors like the 503 error already brought to the developer's attention on the Github Issues page for Playlet. (https://github.com/iBicha/playlet/issues/501).
Also unable to use the web app via browser as suggested by developer so something is a bit buggered at the moment.
I'm sure it will be functioning soon. (just something going on with the backend which was the workaround to the invidious instances). The Invidious guys are also still dealing with some issues as well.