I would for safety sake work your way through the list on the WD site from top to bottom: (As per your link for your drive.)
Firmware update --> To ensure at latest version
Format --> With latest software
SES Driver --> Install latest SES driver
Perform Smartware update --> Update the WD SmartWare Software to latest version.
**** FOLLOWING THE WD INSTRUCTIONS WILL WIPE THE DRIVE CLEAN. BACKUP ANY DATA ON THE DRIVE YOU WANT TO KEEP, FIRST <<<VERY IMPORTANT>> ****The idea is to always ensure the latest and 'matching' firmware/software is used.
Mismatched firmware/software can on 'for any system' for lots of difference software cause unusual problems, instabilities or failures.
e.g. The firmware on a Raid Controller is
older than the Driver software.
If the new firmware has changed the system calls it understands, the
old firmware will fail when the
new drivers make the wrong system calls.
If you have followed the instructions on the WD pages in the order it is posted, it ensures you have matched what WD want you to do.
At that point if you still have a problem you can ask WD and avoid the 1st thing they will ask which is 'did you install ALL the updates as per the instructions on the site'.
In terms of an alternative I cannot say as it depends on what you would find convenient.
Rar, Zip, etc files can be password protected, but that requires you remember the passwords.
(Passwords can be cracked if you have enough time and a very large dictionary list to try)
You have to assess what you trust and how much risk you are able to stand.
Personally, I don't like relying on software to encrypt a drive if I have no alternative way to get the data if the software crashes/corrupts etc
If you keep multiple copies of the data in different places, using different encryption then at least you have some cover. (That may be too much effort
)