Trying to reactive my iMessage but it keeps saying "network connection error" any tips?

i Have an IPhone 4, turned off my iMessage while camping and now that I'm home and on my wifi trying to re activate iMessage it keeps showing me a "neteork connection error" I know I'm connected to wifi be im using it to post this lol. Any tips? My last IOS update was like the 7.2 update. I am under the understanding that the iPhone 4 DOES NOT support any of the more recent IOS updates which is why it's still the 7.2