New Linux Mint Update resulted in login loop

[Cosmo.]

That's a good sign, but I'm not sure what Cosmo. was expecting, so we will wait for his feedback.

That is easy to answer. I wondered, why the login loop reappears. A full disk can get excluded in this case, so some files in user's home, which are critical for login in (.dmrc and others) might have wrong ownership. I wanted to get a confirmation or an exhausting for this suspicion.

Of course you are right, it looks good.

We are now not so far away from the point, where a Timeshift restore is needed. But there is one idea left:

Create a new account and set this for automatic login. Then reboot. Does it log in here?

[Cosmo.]

Another point, I am not sure, if this had been discussed here already. (At least by quick reading I did not find anything.)

Did you try to load in the grub menu to load the previous kernel? If not, do this.
You mentioned in the starting post a FF update and a kernel update. The FF update can get excluded here, so loading the previous kernel should solve the problem. If not, than anything else and not that update has the culprit.

P.S. In case, that my previous advice did help, you can omit this.

[chhejr]

That's a good sign, but I'm not sure what Cosmo. was expecting, so we will wait for his feedback.

That is easy to answer. I wondered, why the login loop reappears. A full disk can get excluded in this case, so some files in user's home, which are critical for login in (.dmrc and others) might have wrong ownership. I wanted to get a confirmation or an exhausting for this suspicion.

Of course you are right, it looks good.

We are now not so far away from the point, where a Timeshift restore is needed. But there is one idea left:

Create a new account and set this for automatic login. Then reboot. Does it log in here?

I created a new user and restarted the computer. When I try to login with the new user it works no problem. But when I try to login with my old user account it still produces the same login loop problem.

[chhejr]

Another point, I am not sure, if this had been discussed here already. (At least by quick reading I did not find anything.)

Did you try to load in the grub menu to load the previous kernel? If not, do this.
You mentioned in the starting post a FF update and a kernel update. The FF update can get excluded here, so loading the previous kernel should solve the problem. If not, than anything else and not that update has the culprit.

P.S. In case, that my previous advice did help, you can omit this.

I haven't tried this yet. Should I proceed with this or would just deleting my old user account and just using the new user account from now on be the way to go? And if I should try to load the previous kernel, How do I do this precisely?

[SMG]

I haven't tried this yet. Should I proceed with this or would just deleting my old user account and just using the new user account from now on be the way to go? And if I should try to load the previous kernel, How do I do this precisely?

If you delete your old user account, you will lose all your bookmarks and software program settings associated with it. You might want to leave the old account there until you are happy you have everything set up on the new user account.

With regards to changing to a different kernel, I don't think that is the issue, but it is handy to know how to do it so I will give you the information.

To boot into an older kernel, bring up the grub menu, select the Advanced Options, and then select the desired kernel. (Usually, you will be selecting a kernel without (recovery mode) after it.) If you do not normally see the grub menu, repeatedly tap the escape key during boot to bring up the grub menu (for a UEFI boot computer like you have).

If that does not work, see this post for how to edit grub to get the menu to show.

Linux Mint automatically boots into the highest number installed kernel. Using the method I just described is one one to boot into a lower number kernel, however, if you are booting into an older kernel because there is a problem with the newer kernel, you will want to use Update Manager to remove the newer kernel so you do not have to do that for every boot cycle.

[Cosmo.]

I created a new user and restarted the computer. When I try to login with the new user it works no problem.

Great, it means, that the problem is related to your account. It also means, that a Timeshift restore would (most likely) not have helped, because with default settings TS does not touch the accounts. And further more it means, that the cause for the login loop is on a place, where we did not yet look at - and at least I must at first think about, where this might be.

This result also means, that loading an older kernel will near to sure do not good. But on the other hand, if you do it as described by SMG, it also does nothing bad. So try it, it is a one-time-method, that means, with the next boot the current kernel will be loaded again. Perhaps we get a surprise.

Deleting your current account and continue to use the system with the new account is of course an option; it means, we will get in any case at the end a workable system. But perhaps we find another way.

In the case that we do not find an alternative, we will guide you to preserve your user data, inclusive browser bookmarks, e-mails (if you use e.g. Thunderbird) and whatever there might be. But I would like to find the real culprit, just out of my own curiosity. Be noted, that this might take perhaps a little bit more time. So tell us, if you have the needed patience or not.

But in any case: Do not delete your current account at now.
What you should do: Backup your complete home (inclusive all hidden folders) to an external drive!. You can do this either from the old account (after having it set again to let you log in) or from the live system.

[motoryzen]

Given the wise recommend to back up the home folder..I believe there is a one line rsync command that does that easily and well enough.

I found it on EzeeLinux.com via a YouTuber named Joe Collins.

I say this because the last few times I tried backing up my home folder via just left click drag aka copy n paste...it gave me a few errors and it didn't back up the entire home folder (LM 20.3 cinnamon here)

Unless someone here beats me to it, I'll happily provide that exact command when I get home from work later this afternoon to make that process easier for ya.

[Cosmo.]

I say this because the last few times I tried backing up my home folder via just left click drag aka copy n paste...it gave me a few errors and it didn't back up the entire home folder (LM 20.3 cinnamon here)

This does not bring us here any further. If you want your problem getting discussed, create an own thread for it.

[motoryzen]

I say this because the last few times I tried backing up my home folder via just left click drag aka copy n paste...it gave me a few errors and it didn't back up the entire home folder (LM 20.3 cinnamon here)

This does not bring us here any further. If you want your problem getting discussed, create an own thread for it.

What are you talking about? The idea of backing up the home directory was mentioned..

I simply mentioned a good method of doing exactly that.

I didn't say anything about needing help with a problem of mine.

[motoryzen]

In the case that we do not find an alternative, we will guide you to preserve your user data, inclusive browser bookmarks, e-mails (if you use e.g. Thunderbird) and whatever there might be

I simply made a short explanation to back up my reasoning behind using rsync versus simple copy and paste. (Shrugs)it's not like it was unproductive wall of text.

[SMG]

Moderator note: beeman's issue, which is different from the one in this topic, has been made into a new topic as per the forum rules New Linux Mint Update Bricked My Laptop.

Please do not add your issues to someone else's topic. It makes it hard for those helping when there are multiple problems from multiple people in a topic.