Numbers for mac will not let me add more than 15 conditional highlighting rules
Numbers 4.3.1 (5249) for High Sierra 10.13.3 running on a Mac Pro (Late 2013) 3.5GHz 6 Processor 32GB.
I was typing in 18 rules, and it let me, but rule #16 would not execute. I deleted all rules and started over. When I hit rule #15 it would not respond when I tried to add another rule. Nothing complicated about the rules, just set a cell color when the number is between two numbers. It creates a color contour map. What could cause this behavior? It feels like the program hit a bug and perhaps corrupted the internal database. Is this a known bug?
Mac Pro, Mac OS X (10.6.7)