[Samsung Galaxy Tab A series Guides, News, & Discus] DJBhardwaj:
Okay, so I found some spare time to verify that the method still works (using the latest FW and Magisk). I have attached an image for confirmation.

Here's a log of the things I have updated in the tutorial. It seems like a good idea to do this so that I can easily track the things I have changed and when. A copy of this log is also present in the tutorial for users who are new.

Log:

Added more info about the warranty. It seems like some users are still not aware of how KNOX affects the warranty. If you're getting into software modifications such as rooting, I expect you to have some prior knowledge about such things.

Redacted the part where you needed to change Magisk's update channel under Step #5. Not needed anymore as Magisk v21.x was released to the Stable channel in January 2021.

Replaced all instances of "Magisk Manager" with "Magisk App". Starting with Magisk v22, Magisk Manager is gone and merged with the core Magisk. It's now called the "Magisk App".

Now, for users who have faced issues with this method. The error you're seeing is caused by the Prenormal KG state being in effect. You will only get this error IF you do something that's not mentioned or skip something in the guide.

So, what do you do after that? It's quite simple actually. First off, restore the official FW via Odin. Then boot into the OS, connect to the internet, enable Developer Options, and verify that "OEM Unlocking" is present and greyed out in an ON state.

Then re-attempt the tutorial. Make sure that you do not deviate this time, I know you would believe that you didn't, but we all can make mistakes. So just cross-reference each step while attempting.

More importantly, after you have flashed the Magisk Patched TAR and performed the factory reset, make sure that you boot straight into the OS, connect the tab to the internet, and do the initial Magisk setup. DO NOT REBOOT the tab before doing this.

While I personally didn't face the issue, I believe this is where things might go sideways, because Magisk needs to run its code to complete the rooting process. If not, Samsung's ugly security features will kick in and show you the "Only official binaries are allowed to be flashed" error message.

If you still have doubts, drop in a comment. I am sure you'll get the help.

At last, I want to bring up something that I didn't wanted to. I received a PM from a reader of this thread expressing his frustration on why I was ignoring the thread and that this tutorial was "tricking" you guys into bricking your devices.

I have a personal life aside from XDA, and I do not get the time to visit the forums on a daily basis like I did until a few years ago. If it's important, I ask you to mention me in the comments so that I can receive a notification.

Next, the method is nothing new or special. It's the one provided by Magisk's creator John Wu himself (like I mentioned yesterday). It's being used by thousands of users in and outside the community.

If you have come across an unusual error message, please do not go on blaming others for your mistakes/errors without valid proof.

Going through the last few pages of this thread, you will find users who successfully rooted their Tab A7 using this guide.

I, or anyone in this community, does this voluntarily to help the users. We are not being paid for the effort or time we spend writing down guides or developing ROMs. This community works by supporting each other, by sharing our knowledge about the things/technology we so love.

If you face issues, I request you to be patient, read, and ask the fellow community members for help by providing some constructive information.

Thanks.