Error 0x8007045D

Hi Guys,
This is the second time I lost a data file because of this.

I have a shortcut on my Windows desktop to a file inside my vault.
When ever I unlock my vault, I can open the shortcut (.txt) file and make changes to the file (in the vault).
From some reason, when I try to open the file now, I am getting an error:
“Cannot open the file, Make sure a disk is in the drive you specified” (it is, nothing has changed).

When I try to directly open the file in the vault, I get the same error.

When I try to copy the file from the vault to the desktop, I get an error:
“Error 0x8007045D: The request could not be performed because of I/O device error”

FYI, the file size, is not 0
When I try to edit the file with Notepad++, I get an error:
“Can not open file…”

Any idea on how this can be fixed?
Your help in this matter will be much appreciated.