Hello,
In the last months the SD card (32GB) of the MM were after 2 weeks full of data.
I tried 3 times to find the problem, but at least I made it completly new.
Today the SD card was full again and I found out, that the MagicMirror-error.log was about 24GB big.
So I deleted it and the system is working again.
But why was it so big? Because of the amount of data I could not open ist.