Help! I successfully changed the clock to the ostrich font. But after trying to change back to the default font, now both the standby screen and the lock screen are completely black. (except for the status bar area on the lockscreen.)

I can tap and swipe to get into the phone, (which works normally), but the 2 lockscreens stay black, even after restoring from a previous backup. Is there any way to restore my lockscreens without having to re-flash?