Symptoms

After entering the correct password in LightDM, the screen turns black.
The mouse cursor may still be visible, but Cinnamon never loads.

This can happen on a fresh Fedora Cinnamon installation, especially when the system receives a broken hostname from DHCP.

Cause: Hostname Is Set to an IP Address

Check the hostname from a TTY.

Press:

Ctrl + Alt + F3

Log in, then run:

hostnamectl

A broken setup may look like this:

Transient hostname: 192.168.2.5
Static hostname: (unset)

This means DHCP/router assigned the IP address as the hostname.

LightDM or Cinnamon may attempt hostname/network resolution during login and hang indefinitely.

Fix: Set a Static Hostname

Set a proper hostname:

sudo hostnamectl set-hostname home-pc

Use any simple name you want:

desktop
fedora
home-pc
gaming-pc

Avoid:

192.168.2.5
hostname.localdomain
random.router.domain
spaces
special characters

Verify:

hostnamectl

Expected result:

Static hostname: home-pc

Fix /etc/hosts

Edit the hosts file:

sudo nano /etc/hosts

Make sure it contains:

127.0.0.1   localhost
127.0.1.1   home-pc

Replace home-pc with the hostname you selected.

Save the file:

Ctrl + O
Enter
Ctrl + X

Reboot:

sudo reboot

After reboot, login should work normally.