iMessage keeps crashing when I try to print out message history.

I am so sorry for your loss. I have been talking to Apple about the same issue. Based on my experience do NOT update to Ventura until you archive/print your daughter's messages. I am not an expert, so I will try to be as clear as I can. I have always archived (print to PDF) my family's messages. When Apple started redacting the photos (which makes no sense as you could screen shot or drag or download) I got Affinity Photo so I could laboriously remove the black box layer from the "group" and then print or save as PDF. Trying to archive yesterday, I could do it with all but my longest family thread (iMessage kept crashing) just like your experience. When I called Apple, they had me make a new user "test" profile on my MacBook Pro, sign-in to my Apple account on the new profile, and open iMessages. When that didn't work (messages didn't show), they had me update to Ventura. Today, a fellow at Apple helped me find the iCloud spot in iMessages so the message threads would sync. I then saved the long thread as a PDF, put it in my iCloud account, and moved it to my regular desktop, BUT when I went to remove the black boxes with Affinity, I learned that Apple has changed the redaction with this newest update so there is no way to remove the top black layer. Based on my most recent call, there is no way to separate or reverse the redaction (it isn't a matter of layers anymore). (Again, this is foolish as you could screenshot, download, or drag any photo.) Practically speaking, what this does (and the Apple folks including the higher up people could give me no reason for this) is make it so you cannot keep the photos in the printed or PDF-ed record of the thread.

So, if you aren't in Ventura, you might try the above. I would sure call Apple to have them walk you through it, and I wouldn't delete anything until you were sure you have the record you hoped to preserve.

Sorry this is so long. I am not a tech-expert. Just hoping to help you through my experience.

I was able to save the longer thread as a PDF once I made a new user profile on my laptop (but used my same Apple ID). In the new profile (I just named it "test") I signed in and opened iMessage and synced iMessage to my cloud. (So I had two users with the same Apple ID and iMessages...one was me; one was a "test" profile.) Ostensibly, that was to get around whatever was glitching on my own profile?? Once the thread showed up on the new profile, I could save it as a PDF. Then I put the PDF into my cloud document folder. I went back to my regular profile. Took the PDF out of the cloud folder, and I was set. (Except for the new Ventura redacting of photos.) I then deleted (as advised by the Apple folks) the "test" profile. For the moment, in spite of Ventura, I am okay as the one thread I needed (this time) was also on my husband's laptop (didn't even think of that before all of this), and he hadn't upgraded to Ventura. I made a PDF of it on his computer and sent it to my machine. This meant that I could use the Affinity Photo to remove the black layer on the "group" for each photo and save the thread intact. Not sure how I will archive in the future....I am not hopeful that Apple will remove the redaction in their new OS. Hope this helps you. It is hard to think how to make it clear. Again, I am deeply sorry for your loss.

Hi montanamag,

Our condolences are extended to you and your family during this tough time. Regarding being able to print the thread, do you have this same issue with other threads as well? This can help narrow down what's causing the issue. If it extends to other threads, you may want to try rebooting your Mac in safe mode to see if there are any startup programs causing this issue. You can learn how to access safe mode here: Start up your Mac in safe mode

If your daughter used Apple devices you may find this resource helpful: How to request access to a deceased family member's Apple account - Apple Support

Additionally if the issue persists you can reach out for support here: Get Support

All the best.

Take care.

montanamag,

Another thought is to copy the messages and paste into a Pages document, and then you can save that as a PDF and print from there.

https://support.apple.com/guide/mac-help/save-a-document-as-a-pdf-on-mac-mchlp1531/12.0/mac/12.0

We wish you the very best.

montanamag,

Were you able to try copying and pasting the messages into Pages and then exporting? What happens when you give that a try?

Convert Pages documents to PDF, Microsoft Word, and more - Apple Support

"Convert a Pages document in Pages for Mac

If you want to open a Pages document in another app like Microsoft Word, use Pages to convert the document to an appropriate format.

1. Open the Pages document that you want to convert.
2. Choose File > Export To, then select the format.
3. In the window that appears, you can choose a different format or set up any additional options. For example, you can require a password to open an exported PDF, choose to use the table of contents in an exported EPUB book, or choose the format for the exported Word document.
4. Click Next. 
5. Enter a name for your file, then choose a location for the file.
6. Click Export."

Take care.