Can't mount disc image file, "The Disc Image File is Corrupted" Recently, I tried rooting my phone, a Huawei Honor 6x.
I had troubles when trying to flash the TWRP file, however.

I downloaded the disc image file directly from TWRP's website, here.
What I was supposed to do next was use Command Prompt to flash this TWRP disc file. It produced the following error:


Intuitively, I then opened the disc file directly, and it gave the error, "Couldn't Mount File, The Disc Image File is Corrupted"

I think this may be the problem, but on the directions I received, it said that I should download the "platform tools from the Android SDK", and "From the SDK Manager, download only the platform-tools to get adb and fastboot binaries." Now, I have already downloaded adb and fastboot, and once I finished downloading, it opened a program called Android Studio, with no information about platform tools.

I read about a similar question here, but the answer was unclear to me. If anyone could explain his answer, or figure out my problem, that would be awesome.
It's simple - you chose the wrong recovery -the one you linked to is for Huawei P9 lite

Your device doesn't have an official TWRP but has a unofficial TWRP linked here

TWRP meant for one device model cannot be used for another. Period

That's exactly what the other answer was saying.

Please take the trouble of reading the relevant forums in XDA to be aware of the device specific techniques.

Next, TWRP cannot be opened at C:/ of your computer

You need to set up adb (press on that to read the wiki. You don't need Android studio for this - it's meant for developers and occupies memory unnecessarily. Uninstall that and read the next paragraph carefully to install what is required for this purpose

To set up adb see instructions here Is there a minimal installation of ADB? and How to install adb

It is strongly recommended that you read and understand what you are doing with a rooted device (as you say you have rooted it). Consequences can be very very unpleasant and you could end up holding a paper weight instead of a phone