How do I unblock my wireless router?

Question

You Tube will nolonger stream to any of my home devices - Ipad, Iphone, PC.  Have used if for years but all of a sudden it will do everything normal up to pushing the play icon and then nothing will happen.  But that seems to be the only site that does this.  Similar sites all work and play just fine on all these devices.  But if I connect any of these devices to a different WiFi, You Tube works just fine on them.  So it seems that something in my setup will no longer allow You Tube videos to stream.  Have tried to reboot the router by turning off and back on to no effect.  Anyone ever encountered this?