Thanks for the image and your message.
> From some research I saw that this is a critical error so naturally I am worried
Excuse me, but it is not really true in this case.
If you examine the S.M.A.R.T. page you sent (displayed in Hard Disk Sentinel) you may see in the Status column:
Advisory: usage limit exceeded
This means that the attribute itself is NOT critical: this attribute generally does not play important/critical role in determining the health of the disk drive.
In many cases, this attribute suggests only a minor cable/connection issue (not a real problem with the hard disk drive) and (especially if the count is 1 only) the hard disk usually has no problems/issues at all.
For critical attribute, you'd see "Pre-Failure: Imminent data loss predicted" there (and much lower Health % on the Overview page).
Generally if you select any attribute, then in the bottom right corner, you can check what kind of information the attribute should represent.
If it shows "Critical" then the attribute is really critical and should be used as important factor to determine the actual, real status (and health) of the hard disk drive. If I'm correct, this is not the case for this attribute, just for others.
This is why the Health % value is so high - as the current numbers do not indicate a "failure prediction" status (when the Health would be lower).
Even if not critical but because in some rare cases, this attribute can indicate real hard disk problem (when its Data field would be higher) Hard Disk Sentinel is sensitive enough to use and as you can see, the Health is "only" 99% (not 100) but it does not mean that the disk is about to fail of course, just an indication of a very-very minor issue. A possible change/further degradation may indicate real problems, so if this attribute (or others) change, then you'll probably see lower health value.
> should I go and ask for a warranty replacement of the drive? or is this a false alarm ?
The text description probably does not suggest warranty replacement and/or replacement at all (probably exactly the opposite).
I see no "false alarm" in the software or by the drive in any ways.
But if you are not sure, I always suggest to (regardless of the displayed values in any software) perform some tests, ideally the combination of hardware and software testing as suggested at:
exactly to reveal possible issues - or confirm if the status is stable and the hard disk is safe to use.
If the disk drive contains data (so it is not possible to use write-type tests), I suggest only
1) Disk -> Short self test
2) Disk -> Extended self test
3) Disk -> Surface test -> Read test
of the tests in Hard Disk Sentinel.
If you prefer, you can use Report menu -> Send test report to developer option now (before the tests) and then later, after the test(s) completed.
This way it is possible to check the disk drive, verify possible changes/degradations too.