Update the firmware and you may be able to delete it.
There was a bug in an older firmware where you could break scan templates simply by adding a description to it, or copying one.
I'm pretty sure the device will need to be wiped though, but try the update first. If that doesn't resolve it, your best bet is to wipe the device via the Erase all customer data option, which is only available in the newer 073 firmwares.
Machine Status > Tools > Device Settings > General > Erase Customer data
Be advised, that will wipe all data, so you would need to do the setup from scratch, if you use a Clone file, make sure it does not contain the scan setups because it will just put the templates back on it.