Okay, we can scratch this - but I am still curious if it is just me or if the Epic version is broken.

You'll have the same game on your Ubisoft account too. You could uninstall the Epic version and install it in Uplay?

JC4 is from Square Enix, why would it appear on uPlay? I thought account linking just happens with Ubisoft games (e.g. Assassin's Creed Syndicate).

Oops, for some reason I confused it with Far Cry. Thanks for correcting me!

I am not even that much interested in Just Cause 4 but I am really curious if there's something wrong with my PC :)

Are you launching it from Windows 10 or an earlier OS version? The error message I get I thought was related to me trying to run it on 8.1

I am trying to run it on Win7.

There's your answer. The dll required was first shipped with Windows 10. Even 8.1 won't run this one.

OK, I was mistaken.

Checking the store page, I found this shouldn't be the case.

Minimum reqs state
Windows 7 SP1 with Platform Update for Windows 7 (64-bit versions only)

Recommended reqs state:
Windows 10 (64-bit versions only)

And then another search today dug this up:
https://www.reddit.com/r/JustCause/comments/g2n4s0/dll_errors_please_help/

You're a lifesaver. I was already thinking my OS was broken. So it was not me it was Epic. They probably only offered the Win10 release. Well - maybe they will fix this. Thank you for digging this up.

Yeah, just stay tuned. There's been a massive flood of support tickets regarding issues with the Epic version hitting Enix yesterday and today, for this dll issue and others (W10 users are reporting dll issues as well I think). I don't think they properly tested the release (possibly due to most of the staff working from home lately) so at the moment it's borked for a lot of people.

https://www.reddit.com/r/JustCause/comments/g2iqp1/dev_please_tell_us_more_about_your_issues_with/

- The W7 Platform Update (KB2670838) adds many things including updating DirectX 11.0 to 11.1. IIRC, one of the newer v2 patches of Shadow Tactics: Blades Of The Shogun requires this to avoid showing a pink / purple screen on startup under W7. You can download W7 Platform Update from here:-
https://www.microsoft.com/en-us/download/details.aspx?id=36805

- If you're missing "api-ms-win-core-synch-ansi-l1-1-0.dll" specifically (as mentioned in the Reddit thread), it was apparently included in update KB2999226 that can be found here:-
https://www.microsoft.com/en-us/download/details.aspx?id=49093

- If you want just the specific .dll to place into Windows\System32 (which may or may not work), then someone uploaded it here from the post marked as "Best Answer" in this MS Support Thread:-
https://answers.microsoft.com/en-us/windows/forum/windows_7-performance/windowssystem32api-ms-win-core-synch-l1-2-0dll/de214e6f-3e64-44fe-aa93-e217761b15ad

- It's possible that the game is a W10 exclusive. There's already at least one W10 exclusive game here on GOG like that (Six Ages: Ride Like the Wind (and possibly Decay of Logos too)). Ideally, someone could test the Epic version of Just Cause 4 on W10 to see if they can get it to run without the Epic Launcher. If it does then I'll add a note about W7 compatibility. If it still doesn't run under even W10, then it's possible that it's simply locked to Epic and / or has Denuvo in addition to unrelated W7 compatibility issues.

I already had the platform update installed and I just installed KB2999226 (which strangely enough was not shown as being uninstalled in my update history but which I still was able to install). After hours and hours of trial and error I uninstalled the game yesterday so first I'll have to redownload it before I can test. Just like Braggadar said, according to the specs it should NOT be a Win10 exclusive so I will download and try again. Thank you for your help.

Edit: Tried it. Still getting the same missing DLL message on Win7 even after installing KB2999226.
Btw: The DLL missing for me is a bit different. It is "api-ms-win-core-console-l2-0.dll".

Now they've changed the requirements for Just Cause 4 on Epic to Win10 - they still missed to change this on Steam as well ... but yes - that's me done testing until I upgrade.

Just Cause IV worked for ten months with Windows 7 until the October 15th patch. They purposely broke it because they didn't want to support 7 anymore. The only way they're getting more money from me is if the first three games are released here.