So my radio is giving this 450709 code & I can't get the radio to work

Hello, That is likely just a software issue, and that code may be the security code for your unit. Either way, write it down just in case it goes away, and contact Subaru to find if this is common. If it is common, they can likely flash the radio with updated software.

Like most modern vehicles, the radio has a code that needs to be entered after the battery is reconnected. This is to make it undesirable to steal the radio of a vehicle. You should have a code given in one of your manuals. If not, then you may need to call a Subaru authorized dealer with your VIN number to receive the code to enter and allow your radio to work again. I have had this issue on radios in vehicles dating back to the mid-90's.