I strongly doubt that you need to reflash to get it going again, since everything you flash can't be changed later, it's a read-only filesystem. An app.bin or osd.bin might produce strange bugs and effects but they should be gone once you boot without usb drive.
The only thing an app.bin or osd.bin can change are config settings and these are not touched when you flash.
This OSD MOD is used by quite some poeple for quite some time now and I guess a general bug would have appeared by now...
My best guess is EIRI...
Check if you have EIRI enabled and make sure it's disabled.
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