Cannot restore iPhone due to unknown error(4013)

Hey so when you get that error code specifically it means the computer was unable to give the instructions to the device to restore, so some of the most common ways around this would be to try a different cable or even a different USB port as this can sometimes cause errors, also check to make sure they are clean and don't have any debris in them and if that fails and is possible then try with another computer and then if that doesn't fix it then you might have to take it in for a service

If you see error 9, 4005, 4013, or 4014 when you restore your iOS device

https://support.apple.com/en-us/HT201444

Many thanks

Erik

So I had this same issue. My iPhone X first got water damaged a month after I got it new, kept using it like that cos all that went bad was Face ID. Read your solutions here and had tried to force restart, use another USB cable and use iTunes to restore. While nothing works so far.

So I guess that the mostly problem appearing after water damage is on Charging flex with vibration. Is there any way to keep them clean and dry? Also this help page suggests to temporarily turn off firewall and security software during the iPhone Restore in case they may prevent iTunes from working properly. Will give it a try.

Hey man I'm sorry it didn't work for you, so I think the next best steps for you would be to give apple a ring on your local number and go through the next steps whatever they may be.

Many thanks

Erik