Failed to update Xiaomi MI3 [solved]

For my Xiaomi Mi3, I already downloaded & flashed to Dev ROM Kitkat 4.4.3, stock ROM is Jellybean 4.3
I am currently on build 4.7.11 & as always, MIUI will give a weekly update, so the latest revision is build 4.7.18

As usual, just open the Updater App to check whether if you have any available updates.

MIUI Updater showing if there are any updates

Each update will have their own changelogs.
You can check here if any of the bugs before were fixed or if such an update is even worth it.
For me, I'll just update for the sake of updating, because I'm the type of person who NEEDS to know :)

For each update, you can check the changelogs

Like any decent software, MIUI will advice the user to backup the data first before updating.
Usually there won't be any problems but there is still a risk that something might go wrong, so it's always advisable to backup first.

I find that encrypting it first makes backup faster but you can't access the files from the PC.
Although it is safer, this is troublesome because I always transfer the backup files to my PC so my Mi3 won't be too cluttered & saves space.

MIUI will advise users to backup first (which I always do)

Here's where the problem starts.

As you can see, it starts to slow down & stuck at 99% download/installation.

Updater downloading progress

This is the first sign of trouble.

As I've never encountered such trouble before, I'm not sure what is the cause.

Updater Error when updating

The error log below mentions about error to read. Before that there was another error, but I forgot to take a screenshot of it.

I've tried updating so many times but still same errors.

I've even downloaded the update file & install manually (select update package) but failed.

Next, i tried renaming the file to update.zip, put in root folder, then update in recovery mode, but it still failed.

In fact, I even rebooted into System 1 to update from there, but same issue also.

Error log why can't update

So as a last resort, I downloaded the whole ROM instead which is bigger at 449MB compared to the 50MB update file.

Then I just installed the ROM from the Updater App manually.

Incremental & Full ROM downloaded

Finally!

It worked!

After finished installing, the Reboot Prompt popped out, a clear sign it the update was successful.

Reboot prompt

Don't worry guys, installing updates or ROMs which is more updated is safe, there's no need to factory reset or wipe anything.

You just need to wipe/factory reset when you are downgrading, like from Dev ROM to a Stable ROM.

Below is proof, previous version is gone, and I'm updated already :)

Latest build. The "Relax" part if you keep pressing update :)