OK, we can enter with this username.

To fix this problem, you need to open your SVG logo file with some editor like Sublime Text or default system text editor and add height and width attributes to your <svg> tag like it is shown on the screenshot https://gyazo.com/83fd36b0bb9628bb1aed2bd3d5d063c5
Then you will need to reupload your icons in WordPress Dashboard.

Regards