Stretch installation boots to read only

[Gary Roach]

Hi all;

I Just upgraded from jessie to stretch. I needed a piece of software 
that wasn't available in jessie. Since then, my system boots to a 
command line prompt. Since /dev/sda1 has been mounted ro, Xwindows 
doesn't start. I have to log in as root, run mount -o remount,rw 
/dev/sda1 /, exit from root and then run startx each time I reboot the 
system. If i run mount -a, an error occurs in fstab at line 9 which 
happens to be the mounting instructions for /dev/sda1. I re-wrote the 
line to read /dev/sda1    /  ext4  rw, noatime    0   1 and commented 
out the old line. The error still happens at the same place.

During boot sda1 passes the system check and after hand rebooting the 
system works fine. An fsck check passes with flying colors.  Does anyone 
have a clue as to what is going on here.

Gary R.