1. Flatpaks missing dark GTK theme

flatpak install org.gtk.Gtk3theme.Adwaita-dark

Also see this article about it.

2. Virtual Manager (KVM) ethernet not working

Open this file and add the following at the end right under #firewall_backend = “nftables”.

firewall_backend  = "iptables"

Restart the libvirtd service.

sudo systemctl restart libvirtd

Now it should work after restarting the VM.

Source

3. NVIDIA drivers

If you have a NVIDIA card, I suggest you follow the steps covered in this tutorial created by Fady Osama.

1. Open terminal and type the following

sudo apt install qgnomeplatform-qt5

2. Edit /etc/environment and paste the following:

sudo vim /etc/environment

# fix for broken QT themes
QT_QPA_PLATFORM=xcb

3. Log out of the session or restart the machine.

sudo reboot

Recommended Guides:

Debian Post Install

Debian Apps

Debian Firewall

Debian Better Fonts

Simple fix for those using a US keyboard layout who cannot type “ç”.

1. Create a hidden file in your home directory called .XCompose:

nano .XCompose

2. Copy and paste the following:

include "%L"
<dead_acute> <c>     : "ç"
<dead_acute> <C>     : "Ç"

3. Log out and log back in.

First install the adw-gtk3 package.

Then open your terminal and make the following changes to the environment file.

sudo nano /etc/environment

QT_QPA_PLATFORM=xcb

QT_STYLE_OVERRIDE=adw-gtk3-theme

Optional

GSK_RENDERER=ngl

FREETYPE_PROPERTIES=“cff:no-stem-darkening=0 autofitter:no-stem-darkening=0”