What you downloaded and put on your camera was simply a piece of firmware that allows you to change the boot flag of the camera. IT IS NOT A MAGIC LANTERN BUILD; it is a developers' tool that allows a coder to change the boot flag so their camera can load their code for testing. This is very clear when a1ex wrote just above the file link:
Please find the FIR file for enabling the boot flag on the EOS/PowerShot M50.
Magic Lantern uses a boot flag to tell the camera whether or not to load the autoexec.bin from the Magic Lantern build after loading the regular firmware. If the autoexec.bin doesn't exist, nothing happens.
There is no official ML build for the M50, yet.
Just grabbing whatever files you can find on the MagicLantern site's discussion board threads and loading them is A Very Bad Idea if you're not a firmware coder with the appropriate knowledge and tools to unbrick your camera. If you cannot actually follow the developer discussion from where you grabbed the file, do not load it, it is not for you. It is for the developers.
Stick to whatever's posted in the main builds, and if there isn't anything for your specific camera body, then wait—or contribute—until there is. Keep in mind, this will be a far more difficult port than with the dSLRs, because the M50's code is based in part on the Powershot code vs. the dSLR code the ML developers are familiar with; whole sections of code they're used to being able to rely on aren't there. Again, a1ex observes, further down thread:
It has some bits from PowerShot firmware, which makes it a bit different from all other EOS models. I mean, porting ML is no longer going to be "just" pattern matching; there will be parts of the code requiring wrappers or other "creative" solutions, not required on other models. That's where the difficulty comes from.
Trivial example: I could not find one of the stubs (GUI_Control), so I wrote a function that did the same thing, from scratch. I believe it's present on all regular EOS models (80D, 5D4, 200D, 77D, 7D2 and so on). ...
See also: Is there a way to get Magic Lantern on my newer model Canon?
