There can be two different causes: the volume you choose is encrypted by TrueCrypt, or there is a malfunction of Acronis low-level drivers due to incorrect registry value
This has been fixed
You will need to delete keys and strings from Windows registry to remove Acronis SnapAPI drivers
Uninstall the product. And then install again
Description of the Acronis SnapAPI module
This article explains how to resolve a problem, when Windows does not boot and snapman.sys is mentioned on the blue screen (BSOD), after an attempt to uninstall or force remove Acronis software.
BSOD during computer bootup related to snapman.sys after removal of Acronis software. Windows does not boot in normal or safe mode.