This article is for V2 and V1 3D scanners.
One of the features of modern antivirus and antimalware software suites is management of camera access and activation. Programs like Kaspersky or Bitdefender will often block any new camera attached to your computer to proactively stop users from being spied on by someone with remote access to the computer.
While these intentions are noble, this can also have the unintended side effect of preventing MFStudio from accessing the camera in the scanner. When MFStudio fails to get an image from camera the calibration will fail, as the checkerboard pattern cannot be identified by the software.
Thankfully, there are ways to add MFStudio to the trusted application lists in most anti-virus suites. The process varies slightly depending on what you use, but generally involves locating a settings panel for "Webcam Protection" (or something similar) and adding MFStudio to a "whitelist" or "trusted applications" list.
Bitdefender: https://www.bitdefender.com/consumer/support/answer/2028/
Kaspersky: https://support.kaspersky.com/KIS/21.3/en-US/82864.htm
Norton: https://support.norton.com/sp/en/us/home/current/solutions/v126148153