Jota doesn't have a function to remove or rename file.
I recommend to use file manager application.
My favorite is ES file explorer.
See menu-settings-Toolbar Settings.
You can edit toolbar area,
See Syntax Highlght page and make your conf file.
If you knew Regular Expression and your language, it's not difficult.
Very sorry.
Jota supports only text files. So if your file was doc/xls/ppt etc, Jota can't open it.
If not, try uninstall and install again.
It may occur to auto-recognize failed.
If you know original character code, then set it at file opening screen.
Or set default the character code as default. (see. menu Preferences -File Setting).
If you don't know about character codes, send the file to developer.
Auto-update of Android Market will force-stop the application and install update.
So uncheck "Allow automatic updating" to prevent it.
Save your file, menu - file - Share as file and choice DropBox, then DropBox will upload your file.
It's waste effort to write it on Review Commnet on Android Market.
If you really want to solve your problem, mail it for me.