There are some known issues documented with printing Calibri in various operating systems. As you can see in the image below, Calibri doesn't appear as an installed font on my own computer (Mac OS) even though it is indeed installed and available in my Office Suite: The bottom line, Calibri doesn't always play nice with applications outside of the Microsoft OS. I've constantly run into issues in which Adobe Creative Suite has a hard time recognizing Calibri and will often populate files with uneditable, broken font links (which are practically useless). Google docs only adopted the font as an option in 2010. For example, Calibri was released in 2002 and only just found its way into the Mac version Office Suite in 2011. Since this typeface was originally commissioned by Microsoft for the Microsoft Office Suite products that specifically utilized their ClearType technology, Calibri's versatility with products outside of the Suite were less than optimal for quite some time. Here are some of the problems I've had with Calibri and why I try avoiding it.
I agree with some of the other answers here that there really isn't a problem per se and that visually, Calibri can hold its own as a default system font.
