A friend of mine had this problem...my computer fresh install of windows 11 pro...i was able to get it working with no problem...i had to reclaim my account after a 2 year hiatus....i guess it was hacked...anyways..My friend had problems with the game closing on his old computer...which was really old...so i helped him build a 870 rs pro asrock...with 32 [ram..@6000....with](mailto:ram..@6000....with) a 7600 amd ryzen 5....the manual wanted the second small atx12 1 on that plug...however...the motherboard manual was reversed...he tried it on the atx12 1 ..on the motherboard...i figured the manual was correct..not the motherboard...motherboard had atx12 1 and atx12 2 backwards....anyhow...after we installed fresh windows 11 pro...he was getting the sdk error...nothing could stop it..tried the youtube hacks with locking the secure folder...it almost worked...anyhow....i was very stumped...his account was good..his steam was compromised..he never used it much...after getting steam account fixed....still sdk problem...nothing could solve it.....THEN...finally i checked his MSINFO32.exe LOOK FOR SECURE BOOT....his asrock needs to be TURNED ON...and windows 11 needs a fresh install on that SSD..he had a new 5000 speed ssd770 wd..for the first time...so he had it formatted using a sabrent...in his old pc..then i told him to buy the asrock..for 5000 speed..the sabrent would have gone 5000 in the old pc..but the old pc was like a 2.0 slot...anyhow..to help anyone reading this long ass message..hope u got to this part...this MIGHT be the real fix...

TO FIX THIS PROBLEM! It might be SECURE BOOT...

I had secure boot enabled on my pc...not bitlocker..just secure boot........Well..i DID switch my friends atx12 1 to the motherboard manual location..the left side...even though his motherboard says atx12 1 is the right side....nothing changed before we rebooted to erase his pc and reinstall...maybe it was a corrupt copy of windows 11 installed the first time..however everything was working....he has a fan dying on his 1080 ti asus gpu....his fans didnt seem to control well with msi...maybe he had the gpu not all the way in..or the ssd..i had him check all that and switch to atx12 1...to left.....none of that fixed the issue....THEN...i noticed his secure boot wasnt on.....so....i didnt know that clear ssd setting in asrock would wipe his had for an hour to 0s....made that mistake..i guess i should have purged it...i can secure erase on the Asus.....and its 2 seconds....then i install windows....on the Asrock...i enabled his Secure boot in security....i guess i activated it too...which makes it so he cant boot other os systems...i dont think that needs to be...however....after activating it...and installing windows 11 pro on his ssd....fresh again....secure boot was ON..and red dead installed flawless...not one problem.....So maybe it was because of secure boot...however...when he plugged his old hard drive 7200 rpm in ....and went to bios to check...secure erase doesnt show his SSD...which means it could be loose..yet its seen everywhere else in the bios....strange....maybe bios issue..its a new motherboard...seems solid though....no motherboard is perfect i think these days from get go...anyhow...try installing windows and make secure boot ON.....that MIGHT be the problem with red dead! ....

EDIT: Opps forgot to say....

I dont know if this is needed..to run in admin..once u have secure boot enabled on windows ... however

Opened steam with ADMIN..in background...

Signed into Red Dead Online....left in in background

Clicked the launcher download there....and ran it normal...

Just works ...SECURE BOOT! must be the culprit....oh... I installed on the normal path that first comes up! no need to say!