Changed device DPI now stuck in a bootloop Device: OnePlus One
ROM: MultiROM with CM11s as internal, and CM12 nightly as secondary
Recovery: TWRP
Backup location: USB OTG
Backup method: Online Nandroid Backup application


So I have quite a dilemma on my hands. I wanted to try something, so I installed a root DPI changing app. I must have set it incorrectly because when I rebooted, everything was so large that I couldn't even unlock the device.
So I followed the application's advice, I copied the build.prop backup to /system. And I went into a boot loop. Then I tried copying the stock build.prop for my device to /system, but it didn't help any.
Everything else seems to work fine. I have TWRP installed, and I have a good backup, but it's on a USB drive, and the data partition is ~6.5GB, so it won't go back on my phone. So here are my options, as I see them:

Fix build.prop, of which I don't have the original file.

Problems:

I have no idea how to do that.




Restore from my TWRP backup.

Problems:

I have the backup on a USB drive.
TWRP doesn't seem to want to recognize that there is a backup on the USB OTG.
The data file is 6.94GB (over Android's 4GB file size limit), so I can't move it back.




Dirty re-flash the OS while keeping my data.

Problems:

I don't know how to do that.
I've heard that problems persist if that's done.




Wipe everything and start from scratch.

Problems:

Obviously, I don't want to do that.
The reason for a boot loop after editing build.prop is its permissions.
Just go to TWRP &gt; Advanced &gt; File Manager and navigate to /system/build.prop. Select it and change its permissions to -rw-r--r--. To do that, enter 0644 in chmod and reboot your device.
If you cannot see build.prop in /system folder, go to Mounts and select System in the TWRP home menu.