On 2021 02 06 I had an application refuse to run, presenting with the error "Can't load protection component, OS error 0x7e". What followed was... Somewhat on an infuriating goose-chase. Honk.
The short-story version is: I had to reinstall the vc_redist.x64.exe obtained from Microsoft's latest supported Visual C++ downloads page. As for how I found that out...
The application presenting the 0x7e original was Neural DSP's fantastic Archetype Gojira. I had it on a trial so I assumed the trial had run out, and iLok was blocking it from being opened. No problem, I expected that. Though... It's weird; I'd never seen that popup or error before. Best check the Archetype Nolly too (for which I do have an active licence) just in case.
It gave the same error.
After a while trying and failing to find Neural-related forum posts on 0x7e, and having a few of my other iLok-registered products fail, I wondered if it might well be iLok's Manager itself that was at fault.
This led me to discovering the other available fixes for "my iLok License Manager isn't working!", namely:
Tried them all, in varying combinations. Still nothing. Same error.
Okay, maybe there's something else going on behind the scenes. Let's go to Firefox and-- Firefox isn't working. Oh, it opens all right. And all my saved tabs are there. But any page I tried to open was blank! Even the config / settings windows wouldn't open.
By this point I'm very confused, and more than a little irritated; it was working fine just minutes ago. What happened‽ Okay, Microsoft Edge -> Mozilla KB articles then. Let's see if this helps.
But.
After the second re-installation (maybe I didn't do it right first time, I don't know) I had a new popup. Joy! Progress! But what is?

Ah, promising.
A quick Bing for VCRuntime140_1 showed that the issue (at least a version of it) seems to be a common occurrence; according to this marked-answer reply there is a known bug and incompatibility betwen the 2015 and 2017 Visual C++ runtimes. Sounds legit, let's go to that latest supported Visual C++ downloads page and see what happens... Because I didn't have any VC++ redistributables installed.
Well... I think so.
Firefox magically started working properly again, and I'm able to open all my iLok-managed products. I'll be keeping an eye on it all, but... This sorted the issue for me.