I can see the home for like 45secs
This contradicts what you wrote here:
"Everytime i turn on my 3ds after seconds i got this message."..
I installed a game hackroom,
Not sure what that is. Can't you uninstall it? Or if it's just a bunch of mod/patch files located on your sd card, just delete them from pc.
Note: i'm talking about the patch files and not the game files that're inside the "Nintendo 3DS" folder, if that's the case..
but this started happen before.
What happened before? And how did you get to install this "game hackroom" if it gives you the ErrDisp error after 45 secs? It's not sufficient to install anything (unless it's like a 20mb game or less)..
Firmware Versuib 11.9.0-42U and Luma V11.0
For starters, you're on an old firmware and yet you're using the latest version of luma3ds, that might cause problems but i'm not sure. You should update the system through the recovery mode, but before doing that make sure you have a nand backup, make one in GodMode9..
The strange thing is sometimes happens sometimes no.
You could also check your sd card for errors with
h2testw, you can't be sure it's not faulty until you test it. Backup your data before doing it, obviously. Make to format the sd card as Fat32 32kb cluster size before and after the test. Use the "read & verify" option in h2testw..