iMessage Freezes every time I open

I've managed to fix this after digging in. The freeze up was from an unsent SMS message that was stuck in a weird state. When in iMessage, I opened Preferences which immediately pointed out the unsent message and asked if I wanted to ignore or resend. I ended up deleting the entire conversation to remove the message, but you could have resent it likely as well to get it out of the limbo state. Once this was done, iMessage did not freeze up after opening.

Following the trail created by some of the above posts:

I signed out of iCloud and iMessage on all devices and then back in. Not that that helped.

But then proceeded to find unsent messages in the apple apps...

Not to be found, except with in the iPhone Mail App > OutBox had 3 unsent mails with red alerts on them. I trashed them and

Believe it or not..... I message began to work flawlessly, no freeze.

So, great job Apple for making iMessage dependent on the Mail app..

Also, I couldn't see the unsent Outbox bin on the Macs, only in the IOs on the iPhone for a particular appleID, so go to your iPhone for this fix.

I Never would have tracked this down without the hint from these posts, so Thank You....

I had this same issue too. Anytime I would minimize the iMessage app on my 2018 Macbook Pro, it would freeze the entire system for a few seconds. It actually got really bad and froze the entire computer indefinitely and so I had to restart it.

The issue seems to be with the "Genie effect" animation that the app closes with. By going into my "Dock settings" in "System Preferences," I changed the animation effect to the "Scale effect" and that seemed to fix it.

Best,

Joe

Just a quick update, the macOS 10.14.4 update completely resolved the iMessage issue. No lag/freeze on open whatsoever. No need to resort to turning off "Automatic graphics switching".

Thank goodness. Hope this update worked for the rest of y'all as well!

Also out of curiosity, what are you using to perform a data capture on a specific application?

Wireshark

Ok, I did a capture of my Mac mini and started up the Messages app without any other apps running on it. Doing a quick review of the packets in the capture, I see that Messages used DNS to locate the Apple iCloud server, and then, creates a secured communications channel with it to review all of your iCloud Contacts. This is done before any sending or receiving any iMessages or text message with the Messages app.

I have only around 50 contacts in my iCloud account ... so it begs to ask the question on how many and what type of Internet connection download speed do you have? One potential reason for the initial delay could be that if you have a lot, it could take a bit for Messages to "load" them into memory.

I also have this problem - mid 2018 MacBook Pro.

Just got off phone support with Apple Support and it wasn't too much help. Did the whole NVRAM reset, no luck. Tried in safe mode, worked fine (no lag). Turned off FileVault, no luck. I do not have any unsent messages like some people in this thread, so that can't help me.

What DID work that was very strange - I force quit messages from the Apple menu. Then it will never lag again on re-open... BUT once I restart my computer again it's back to lagging. So not a useful fix at all.

Automatic graphics switching did work for me permanently, but like someone else mentioned, not a viable fix as it will decrease battery life. What do we do from here? Will this get fixed?

Just found an article online how to solve this problem, which relates to iMessage's cache on the system. This is the link http://www.fireebok.com/resource/how-to-fix-open-messages-freezing-on-iphone-and-mac.html

However, I could not find those caches file in Library to remove them, that is how they show to solve the problem according the link above. I came up with the other way is using CleanMyMac to remove the iMessage cache.

It works for me after couple times

Yes, I also have the same issue with the 2018 MAC-13, have they exact same freeze on iMessage and Excel MSO365

However the freeze does not occur in Safe Mode

But a reinstall did not fix the problem.

So it must be in the login settings & interactions, somehow....

Come On Apple!!!!

See if the following article can help:

• Common Apple messaging problems and their solutions - Apple Toolbox

Does this issue only happen with the Messages app on your new notebook? That is, if you open this same YouTube link in, let's say, Safari, does the problem still exist?

Try to clean the system's cache, hopes it solve your problem

I have a macbook 13inch 2018 with the same issue. But I don't have that option to uncheck. Any advice?

I also have this problem on MacBook Pro 2017, macOS 10.14.3.

Automatic graphics switching did work, but it doesn't seem like good solution.