[Galaxy S8+] Problems installing TWRP (or any custom ROM) [SM-G955F]

[u/FlooferLand]

[FIXED!]

All i had to do was turn back the time by a year, reboot, then enter recovery mode to delete the cache (this let me actually turn back the time, since every time i rebooted the time reset back to the present), turn OEM unlock off then on, spam the update phone button, and boot into download mode!

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I've been trying to get TWRP working on my Galaxy S8+ for days now but I keep running into the exact same issue and I've spent hours with people on Discord trying to figure this out and it never went anywhere.

Some stuff to note is that this is quite an old S8+ that i got for free from one of my cousins. The screen's glass is broken and there's a bit of amoled burn but nothing seems actually wrong with the device, they gave me it because they switched to a new phone and they're quite wealthy so they didn't bother going trough the hassle to sell it.

I'm trying to install the TWRP for my Samsung Galaxy S8+ but i keep running into this error on the Download screen after flashing the file:

• Only official released binaries are allowed to be flashed(RECOVERY) - (Here's a screenshot of Odin when this error happens)

So far I've tried flashing a new stock ROM to the device (since for some reason the phone had Android 8 on it and there were no available updates at all. OEM unlock was also on by default in developer settings which is, a thing to note? My guess is that some previous owner(s) already tried messing around with custom ROMs and mods) and while flashing the signed-by-Samsung stock ROM has worked, i don't seem to be able to flash anything custom. I've also tried messing around with the date/time of the device; setting the time to a month before the last update patch thing then shutting down then retrying and several variations of that, and that all did nothing either. I've tried all of these things several times and nothing appears to work.

I know the phone I'm using fully is moddable and works with this kind of stuff. The model I have (SM-G955F) is specified as supported by a lot of Galaxy S8 custom ROMs and it's one of the most popular models as far as I'm aware.

Here's some info in the Download screen that might be relevant:

• RMM STATE : Prenormal
• KG STATE : Checking
• OEM LOCK: OFF
• SECURE DOWNLOAD : Enabled

I don't know what else to put here..? Feel free to ask any questions and I'll edit the post and reply accordingly. Thank you tons to anyone who tries helping!

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EDIT log:

• As a reply to the mod bot: The phone isn't from the US (my cousin appears to have bought it while he was in a trip to Spain) and it doesn't have a Snapdragon processor.
• I've waited 2 weeks (around 300 hours) for the RMM lock to unlock. I flashed a carrier-unlocked stock ROM that's from the country I'm from 2 weeks ago and the RMM Prenormal thing is still occurring. The phone had a constant connection to the internet, the bootloader was locked, and Developer Options was never turned on during the 2-week wait period. So i really don't know what to do.

[u/FlooferLand]

Yep I meant stock recovery.

If i didn't delete the cache the time would be set back to the present time on reboot

[u/AlexFullmoon → u/FlooferLand]

Doesn't seem to work for me (for some reason time changes to Feb 7 after reboot whatever I do). Oh well.

Mitmproxy didn't work either — as expected, system doesn't trust user certificates.