For the sake of completeness, I will write down again here what I already wrote in Issue #2894.
Since a few days I have the problem that I can not use Miranda NG with my Facebook account. I did not have this problem until about two years ago. This problem seemed to have been solved. However, some friends of mine reported that they still can't log in without Facebook blocking their account. As I said, I was unable to reproduce this until now.
On 5/18/2021 I was traveling by train and wanted to use Miranda NG with my notebook as well. So far Miranda NG was only installed on my PC at work and on my home computer.
After installing Miranda NG on my notebook, entering my account details and logging into Facebook with Miranda NG, after a few minutes my Facebook account was blocked. So I logged into facebook with a browser, confirmed my identity and inevitably changed my Facebook password. After that, my account was unlocked again. Since I didn't want my account to be blocked again, I didn't try logging into facebook again using my notebook and Miranda NG.
When I got back home last night, I logged into Facebook with my Miranda NG on my home computer after entering the new password, which I had to change before. Again, at first it seemed like there would be no problems,. However, after about a minute or two, my Facebook account was blocked again and I had to unlock it exactly as described above.
I then tried to log into Facebook again with Miranda. This time Miranda NG was immediately blocked by Facebook, without Miranda NG having a chance to even be online for a second. However, my account was not blocked, but I had to confirm my identity and change my password. I tried again after that, but always with the same result. Every time I logged into Facebook with Miranda NG before, I got the message "Login confirmation required" and had to change my password every time.
Since my login attempts kept failing, I enabled two-factor authentication on Facebook and set an app password. I then entered the credentials on Miranda NG and tried to log in to Facebook. Unfortunately, that didn't do the trick either. I had to reconfirm my identity and change my password again, even if it was just an app password. Please do not confuse, my account was not blocked, I am just asked to confirm my identity and change my password. Sometimes you get lucky and you don't have to change your password.
Out of desperation I tried to enter my normal credentials despite the two factor authentication being enabled and try again. I get an SMS where I am supposed to enter a code. Since Miranda NG doesn't support this type of authentication, I obviously couldn't enter the code. Also on the website, Facebook informed me that an unknown device and browser was trying to log in. I was asked to confirm whether it was me or not.
I even tried deleting the device ID, which of course didn't help.
Unfortunately, Miranda NG no longer allows me to log in to Facebook with my account. Facebook classifies Miranda NG as an unusual device or similar. Maybe it could work if Miranda NG would support the two-factor authentication, but I'm not 100% sure about that either. What is certain is that Facebook doesn't seem to make it easy to log in to Facebook with an external application.
Unfortunately, there is no way to tell Facebook that Miranda NG is not malware or anything like that. Maybe you should try to use the Graph API.
It would be really very nice if there is a solution for this problem as soon as possible. Also for those who have not been able to use it for a while. It doesn't seem to matter how old the Facebook account is or how many posts have been made. Also, it doesn't seem to be because of how overloaded Facebook is. I've had the problem for a few days now. I no longer have a chance to even get online for a second. From what I'm reading here, this problem seems to have picked up again in the last few days.