Failed to execute the command error when trying to start a backup

Hi,

I'm running ABR v11.0.17318 on Win 7 x64.

Recently, I started to receive the following error when I tryr to start a backup:

**************
ProtectCommand: Failed to execute the command.
Additional info:
--------------------
Error code: 41
Module: 307
LineInfo: e6792a5ee190ddb3
Fields: $module : C:\Program Files (x86)\Acronis\BackupAndRecovery\mms.exe
Message: ProtectCommand: Failed to execute the command.
--------------------
Error code: 33
Module: 307
LineInfo: 5d2a9295cc9442b9
Fields: $module : C:\Program Files (x86)\Acronis\BackupAndRecovery\mms.exe
Message: EnsureBackupInvariantsCommand: Failed to prepare the location for the backup archive.
--------------------
Error code: 5
Module: 154
LineInfo: 9a79f20828bc7f3
Fields: IsReturnCode : 1
Message: GetFileInfo call of FileManager failed.
--------------------
Error code: 5
Module: 154
LineInfo: 9a79f20828bcc57
Fields:
Message: GetFileInfo call of FileManager failed.
--------------------
Error code: 7
Module: 4
LineInfo: f35f747b3b21fb3d
Fields: IsReturnCode : 1
Message: Error occurred while opening the file.
--------------------
Error code: 65520
Module: 0
LineInfo: bd28fdbd64edb8bc
Fields: code : 2147942403
Message: The system cannot find the path specified
--------------------
**************

I've uninstalled and reinstalled but no luck. What does it mean and how I can fix it? I desperately need to make a backup so any suggestions would greatly help!

Thanks!