--Traffic from that VLAN still works to other VLANS--
In fact Traffic from that VLAN to other VLANS only worked when "Inter VLAN-Routing" was enabled for the other VLANS (Inter VLAN routing can be seperately enabled for every VLAN). So when "Inter VLAN" Routing was disabled for every VLAN there was no Traffic allowed between all VLANs at all. So I don`t know what this fix should be good for since everything worked fine...