❔ Failed to create component; Invalid URI: The hostname could not be parsed

I am having some weird issue with my Visual Studio and I dont understand what it means. I added a new class inheriting from the Panel control and this broke something in VS which makes it impossible to add a specific other custom control I have in any way. It is not code related since I reverted all my changes through GitHub, yet it still does not work. This is the error message I am getting when I try to place down the control: