Red exclamation mark at top left when booting phone was experimenting( more specifically, trying to flash ROMs) with my Samsung Galaxy J1 Ace(rooted). It was all going well till I tried flashing the TWRP recovery mode. I followed all the steps mentioned on various xda forums but a red exclamation mark appears at the top left of the screen when I try to turn it on, along with the Samsung logo and it the phone just hangs. When I go to the download mode, it shows MDM Download : 0. I tried flashing, using ODIN, other versions of the TWRP for my phone model but the same error persists.

Is my phone soft-bricked?

How do I fix it?

I am trying to restore the original stock Samsung firmware now.

Many thanks.
Alright everyone, I have managed to solve the issue.  If you find yourself in this same error, visit this site to know properly how to fix your SAMSUNG device. 

In short, you need a PC running a Windows OS, a software called Odin(v3.07)[used by SAMSUNG internally, so its legit] and the original stock firmware. Download the proper combo( country-region and phone model).

Hold the Power, Home AND volume down buttons simultaneously for around 5 seconds(until the Download mode comes up).

Then connect it to your PC using a usb cable and run Odin. Now click on the PDA and navigate to the extracted stock Samsung firmware file (MD5 type). Select it and wait for a while, the Odin will take some time (around a minute) to check and process the MD5 file. 

Then click 'Start', let the flashing finish(takes around 10-15 minutes) and voila!