"Low Disk Space on Filesystem root" after installing Axolotl and Podcasts

[dukla2000]

...
Additionally I had tried to follow @dukla2000's suggestion to supplement the storage with an SD card but whenever I put one (an older and a very new & fast model, both 64 GB, both Samsung) the phone does not boot (green LED, black screen & nothing else), no matter whether I format them as ext4, fat or exfat. (I had used both of them for Megi's multi distro image before reformatting them.) What could be the problem?

They both still have a residual bootloader on them but no corresponding operating system files. Clear the bootloader as per instructions here.

[Anna]

That did it! Thank you!

And thank you so much for the link -- the page answers so many questions I had:
--Thanks to scale-to-fit I can now use GPodder (sort of)
-I have learned that GPS actually works (Maps and Open Street Maps in the Gnome Browser still show some address in Frankfurt, Germany, as my location but at least now I know that this is not some random placeholder but that it is actually measured (albeit falsely), so thats a point to start to look for the error.)
-There is a manual on how to "Mount SDcard as /home"; that was one of the next things I wanted to do (though encrypted)

...and I am sure there's a lot more to discover once I read the whole thing.

Great!