OSM inspector seems to be down. Does anyone know of other ways to find the problem in a broken multipolygon?
OSMI is working for me.
This is what I get.
edit: I am trying to figure out the problem with this multi polygon: https://www.openstreetmap.org/relation/168553
It works for me too. Your relation in area inspector below.
https://tools.geofabrik.de/osmi/?view=areas&lon=7.14379&lat=46.21234&zoom=13&opacity=0.59
Thank you very much. It was very useful. Strangely, OSM inspector works fine on chrome and Mac OS, but not on my usual Ubuntu desktop and firefox browser.
I use Opera for Windows and as you see OSMI works fine there. It looks, that your browser is broken and OSMI is OK. 
Firefox has some “improvements” since Version 62.x which blocks some “insecure” pages. I have problems working behind a proxy for example.
If you know the reason you can use “about:config” to disable this “features”.