Level 1239 - I'm unable to complete, it says I need more yellows than were ever available.

I got very close to completing 1239, had a few moves left and had a couple of yellows to mop up.  Then I realised that I actually needed 4 to finish but there were no more yellows or 'tick' candies around.  Now, on starting, I find it's happening again and there aren't 21 opportunities to get a yellow (only 19) so it is impossible.  Also, there has been a glitch which sees one of the bottom row 'disappear' and although it can be invisibly 'switched', it makes life very difficult.  How do I get past this level if it's doing this?