The Message+ app on my Mac (v2.5.5) has been crashing for over a year now. I know there have been a lot of frustrated posts about this exact problem already, but I've done some sleuthing and can provide some more specifics as to the nature of the problem (for me at least). Also, I know someone from Verizon is going to ask a bunch of really basic questions here (and then probably ignore my answers), so I'm going to try to forestall those questions right now.
1) I'm on a Mac running Catalina (10.15.6), and yes, all Mac software updates have been applied.
2) Because we're talking about the desktop app and *not* the web app, it doesn't make a bit of difference which browser I use.
3) Like I said before, I'm running Message+ v2.5.5. There is no higher update available from the Mac store.
4) The crashes do not happen when the app first starts up. Rather, they happen any time I click on a conversation where there is *any* (and I mean any) non-plaintext item (picture, video, emoji, etc.) anywhere in the conversation history. Furthermore, if I type in someone's name in the "Compose" field and that person is someone for whom there is a prior conversation with any non-text item in the history, it will crash.
5) It is possible to successfully send a text message to a person where there is no conversation history at all (or where there is a history that contains only plain text messages), and for them to send a text back. But the minute that a person sends back a text message with any kind of non-plaintext content, or I send them a text with such content, the app will crash if I try to view that conversation (or if I'm already on it). Similarly, I can delete an old conversation with someone, then successfully send them a text message (and they back to me), but the crashing will start the minute there is any non-plaintext content in the conversation.
6) This problem does not prevent texts, even those with non-text content, from being received by the app. I just can't view them without causing a crash.
7) Yes, I've tried completely removing the app (including the remnants it leaves in ~/Library/Containers/com.verizon.vzmessagesmac) and then reinstalling it, with no success.
😎 Yes, I've tried disconnecting the desktop app from my phone and then reconnecting. When I do that, the old text messages reappear and the same crashing behavior happens if I click on any of them.
9) I don't know exactly when this problem was introduced, but it was with one of the upgrades to Message+. In previous versions, clicking on a conversation with non-text content would cause the conversation to be displayed incredibly slowly, and scrolling through it would get slower and slower until sometimes it got stuck completely. Now it just crashes instantly, which is an improvement only from a clarity-of-problem point of view. I desperately wish I had v2.4 of the app since I don't think the problem existed back then, but I haven't been able to find older versions on the internet anywhere.
10 Verizon, do not tell me to use the web app instead. Not only is that not a solution, but as countless people have documented here, the web app is plagued with problems. Sometimes when I sign in with the web app, all my prior conversations are missing. Sometimes the app gets stuck in an endless loop of trying to sign in and refreshing the page. Sometimes the username/password fields are missing on the sign-in page. And the app has its own problems, like sending pictures sideways or hanging completely when trying to send a picture.
I will tell all of you too that I've spoken to Verizon reps on the phone who have candidly admitted that Verizon will be phasing out Message+ at some point in the near future, which is why the company doesn't care much that both the web and desktop apps are so buggy and crash-prone.