I worked with Courtney to solve this issue and based on the system in place; our Certificate and Badge tool will use the information from your "Profile and Preferences" to generate your certificate of completion.
In this case, it seems that your Name field in settings was left blank, which caused the tool to generate the blank certificate. This problem can be fixed by confirming that your user profile includes a name (you can edit the name field by clicking the blue pencil icon), see below:
If the problem persists, we will take another look. @cbsembler will be reaching out to you seperately to regenerate the certificate.