FOSS gamedev and creative worlds

I disable all my mods and I still can't mine the two items, could someone please tell me what is wrong?
I can't mine cactus either, I hit them with my stone pickaxe and nothing happens.
I only have these mods, Homedecor, moreblocks, beds, nether, and computers.
I don't get any errors when I am playing.
Any help is greatly appreciated.

I think cactus and diamonds need stronger tools, e.g. steel or mese.

Cacti need to be mined with axes.

PilzAdam wrote:Cacti need to be mined with axes.

..or swords > stone

Thank-you for all your responses and help