Nowhere I said to uninstall and reinstrall, which is not required. I said to:
- Configure the antivirus to Addon Manager folder to its Exclusions list.
- Run the FSDT Live Update again.
You can verify if this is in fact a problem caused by the antivirus corrupting the Couatl.exe file, if you check its Digital signature. The file is located here:
Addon Manager\couatl\Couatl.exe ( Addon Manager, by default, it's installed under C:\Program Files (x86), but can be anywhere it you changed it on install )
Right-click the Couatl.exe file, select "Properties", select "Digital Signature" and verify if it's valid. If it's not, you can be 100% sure the file has been corrupted locally by the antivirus. The whole point of having a digital signature is precisely to make sure your local file is not corrupted.