Paragon Backup for OS resulted to error pop up

When I am executing the ‘Paragon’ backup for backing up the operating system, an error message pops up. I have done the same before without any problem. Please see the screenshot for the error message. Please help me to figure out the problem and resolve it as well. Thanks in advance.

Backup & Recovery
Operation Failed
VSS: Can’t read volume data.
Error Source: Hard Disk Manager
Error code: 0x12016
