ERROR: GIF Not Showing
For the GIF to show, make sure that your link has the file extension at the end (.gif)
Here is an example URL of how it should look:
https://i.imgur.com/JL1snRo.gif
^^ Notice the .gif extension at the end
On your readme md file, the markdown should look like this:

We recommend using these tools to help you record GIFs on your computer:
ERROR: reference 'refs/heads/master' not found (-9)
This problem has many solutions to it. Here a few links to help you fix it:
SOLUTIONS
If those solutions don't work, you can create another GitHub repo and simply copy/paste your project in that repo folder.
Error: Any issue with Outlets
This is most likely an issue with your outlets. Go to the outlets menu on the storyboard and verify that your outlets are connected correctly.
This can be caused when you create and delete a current outlet and create a new one.
The image below shows how an outlet is made correctly:
The second image shows an outlet that was broken (the broken outlet is the one with a warning sign