Cant do port range forwarding on shadow?

So i go to firewall, fill out desceiption, internal ip, external ports 10000-20000, leave internal ports blank or even try 10000-20000, tci/udp, enable. And it rejects it due to internal port. Seems i cannot do range forwarding at all???

Can you go to Luci and try?

Not sure where to do that.

More settings-> advanced settings

Then after you login, go to Network->firewall

Thanks , i will try that.