Random Enable iMessage Error

This usually isn’t anything on your end if it’s random like that. iMessage can flip out when it can’t decide whether to send as iMessage or SMS, especially if the other person has spotty data or recently changed devices or SIMs. When it fails, iOS throws that confusing “iMessage needs to be enabled” error even though it clearly is.

It can also happen if Apple’s iMessage servers are having a minor hiccup or if the conversation thread is stuck in a bad state. Starting a new thread with the same contact or toggling iMessage off and back on later sometimes clears it, but yeah, it’s usually not your settings or something you broke.

Fletchsl wrote:

I have gone through all the motions to correct this issue, and nothing has helped.

What steps have you taken? Unless we know what you've already tried, it's likely that we'll suggest some of the same things.

If you can't send or receive messages on your iPhone or iPad - Apple Support

It happens randomly. Does it have something to do with the settings on the receiving phone?

It could. Go to Settings>Apps>Messages>Send as SMS and make sure it's set to ON. That setting, despite what many people think, has nothing to do with sendind SMS messsages to Android phone. What it does, is, in the even that a message fails to go as an iMessage (perhaps if your receipient has data turned off), it will be resent as an SMS.