I like to mess with my current theme by editing the plist files using the text editor in iFile. I know it's not a smart thing to do especially when you are not near your computer with which you can reload a good plist file via ssh. This problem hit me while I was about five hours away from my computer and copied and pasted some code into my theme from a tutorial.
This is with DreamBoard. My screen went black but I could get back into iFile by double clicking the home button. The plist wouldn't load into the text editor because there was an error on line number ###. I think it was 262.
To get out of the theme I could delete the theme.plist file and have a working iPad for the next two days and reload the file when I got home. After a few minutes of panic I decided to try to rename the file and reboot the iPad to get out of the theme.
Since I could rename it I decided to try to rename it to theme.txt. Then I tried to use the text editor. Success! The formatting was all wrong but I could comment out the erroneous code, rename the file back to a plist, and see if the text editor would open it again. Further success.
I thought I would let others know about renaming the file to be able to fix a problem, just in case they caused the problem, like me.
Later, I discovered that I could rename the file to theme.p and there are a few more options added to the list. Text Editor ends up in the middle of the offerings.
I also found the option in Settings (click the little gear icon in the bottom of the iFile window to get to settings) to increase the font size in the editor window. The max is 18. I needed that one.
Now to find a way to get line numbers for when I get another error.
Sent from my iPad using iPF - Peace