You can set the interface IP addresses through the console
If I connect directly to my opnSense hardware (hdmi) and starts it up, it does say when it list my interfaces that the lan ip is 192.168.5.19. I don't really know how to continue on this, is it possible to reset the lan ip's to default or something?I tried to login but it said something that it was unable to do that trough this environment (or something similar). My admin user is disabled..
You need to configure your PC to an IP address in the 192.168.5.x/24 network to access the web interface again.