Not booting after December update

Hi!

I am using a rpi2 with SanDisk Ultra 32 GB MicroSDHC UHS-I. I did not know about this issue and I updated two days ago (this implies that I should hav the new PI kernel (4.3.3-2)). The issue is that the rpi2 boots only to the first OSMC screen and then shows a sad smiley face.

I connected the SD card to my Macbook’s card reader and it shows two partitions - fat and ext, and as expected mounts only the fat one. In the fat partition there is no /boot/ folder. However there is a config.txt file, but it is read-only and I cannot save the files after adding the new line. Thus my question is if I need access to the ext partition, or this fat partition is the right one. If fat is the right one, how come I don’t have the /boot/ folder. If it is okay that I don’t have the /boot/ folder, how do I save the config.txt file (I don’t have permissions to save it).

I really hope someone can help me - honestly this situation is unacceptable.

Thanks