Hit O to see the overlay that show the painted mask.
Make sure Density and Flow is not set to 0.
This problem has been going on for days and it's given me nothing but frustration.
YOU have solved my issue. I cannot thank you enough. I have no recollection of changing the value of that slider! Now I can stop what seemed an endless search to figure out what's been corrupted in the software, it was such an obvious yet subtle fix.
Thanks for pointing out such a simple solution and ending my aggravation. You've saved me from an early computer upgrade!
Happy it works for you now
Please mark the thread as solved - that helps others finding solutions - thanks.