I have been struggling for the past few days to run OSMC on a few new RPi’s 3 b+ v1.2 and it really is a hit 'n miss.
I’m using the OSMC tool to flash the micro SD. Been trying on a few different brand of cards (Samsung, SanDisk, Transcend and some chinese brand called Foresee, all HC) but end up with rainbow bootscreens.
I tried various builds from the first to some later releases to the latest ones.
Also tried with LAN or Wifi.
I already had a lot of trouble getting it to work on the pi 3 b non plus version, but I have to set up 8 brand new “plus” versions.