I would try and reset the unit.
Please switch the unit to off and wait until the lights are off.
Hold the function button for 10 seconds while it is still off.
While still holding the function button after 10 seconds please flip the switch to off.
Once the function light begins to blink release the function button and press it again for one second.
Wait until the power light is solid and this will restore your unit.
This process will not delete any data and will only restore the admin password and set the IP address back to DHCP.
It could also be a firewall or antivirus issue. Can you access it from another computer? How about a direct connection your PC using an ethernet cable?