I get that as well on my Galaxy 6. I've found that if I click the arrow on the side of the message it always takes me to the Search function regardless of where in my inbox it goes. However, if I click just above the sender's name it usually opens okay for me.
I've been getting the "wait 30 seconds before posting again" error on every post today. Pretty sure everything I use is Chrome-based (my phone is fairly new so I don't know all the ins and outs yet, and I'm fairly phone-illiterate :look).