Big Sur and Messages No Text Entry Field

Has anyone see an issue where certain contacts do not have a text entry field on Big Sur when selecting them in the list of conversations? I am able to get a field to send a message if I act as if I am starting a new conversation with them.
Yep! I'm going insane. I don't understand how to fix this.
Okay, I fixed it. Here's how I did it:

For each affected contact (I only had one, so I have no idea if multiple contacts present different problems):

(0) Have Messages open, but have the active conversation be one of your working contacts, NOT one of your broken contacts (not sure if this matters, but this is what I did).

(1) Open something in Preview (an image, pdf, whatever).

(2) Click the sharing button (box with an up-arrow coming out of it).

(3) Select Messages

(4) Enter the contact's name (duh)

(5) Enter some text in the provided box

(6) Send

(7) Check your Messages conversations that were broken.

(8) Rejoice

u/mikeportanova is right - you need to share something with the contact outside of messages, but with the selected conversation in messages having a type field. I have no idea why this works, but it does.
Unfortunately, this didn't work - I was able to text from my Mac for about 5 minutes. First message received from the other person, and the message field has disappeared again.
mikeportanova's fix worked for me!
Also experiencing this issue which has drove me insane for the past couple of months.

A quick fix for this, albeit not permanent, is to react to any message in the thread (i.e. thumbs up, thumbs down, heart). This will quickly reinstate the input.

The only other thing I think might be worth a shot is somehow removing all message history from you Mac, essentially so it's totally clean (as if messages has never been setup) and then resync with iCloud messages. Does anyone know how to do this? Where all the associated files and preferences are located?
@ozwoz solution worked for me. Thank you.
@mikeportanova's solution worked for me! thanks so much. My two closest family members' texts had this problem, so you can imagine how often I was having to deal with this. Weird problem, but easily fixed with MikeP's solution. :)
(M1 MBAir user/Big Sur 11.1)
I have the same issue too. I've tried each of these solutions, and they all work temporarily, but then the problem returns once the app is closed and restarted:
  • @mikeportanova's solution: share an item with the contact

  • @ozwoz's solution: do a tap-back reaction to an item in the contact's feed

  • My own previous solution: Click the button to start a new conversation, and find the person's iMessage contact result. This will start a new conversation thread, but it will have all the old conversation in it, and will have the message input field at the bottom.

I hope this problem can be fixed so these workarounds are not necessary!
I had the same issue, just with one contact. It was so annoying. Mike P's fix worked for me. I used a PDF, it didn't work through Safari with a link through tik tok.

Thanks for this help!

I've had this issue since upgrading to Big Sur.

I'm in the same boat as @M_Prewitt...
  • tried sharing an item with contact... works temporarily

  • need to try doing a tap-back reaction... that might be the quickest solution.

  • I've been starting a new message and then adding my wife's name, then starting a new message that way... the reply box appears... temporarily.

The crazy thing is that I only have this issue with one person. One contact. My wife... which happens to be the person I message multiple times, all day long! that's the most frustrating part!

I think macOS 11.3 has finally fixed this!
Big Sur and Messages No Text Entry Field
 
 
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