[Samsung Galaxy S8+ Questions & Answers] Estebandido1232:
Hello.

(backstory, boring) I have an SM-955F from Claro that I've been trying to unlock completely from the carrier. I've had lots of trouble with them and am pending a case with FCC to get out of their claws. In the meantime, I've been trying (without success, hence my posts) to get it working 100% with T-Mobile. I've had T-Mobile for years under a friend's name and couldn't get a device -so I took one from Claro when Puerto Rico was hit with the Hurricane (T-Mobile had no signal for months).

(Little-lot- of info) So, I had the phone updated to Sammobile's PCT 8.0 firmware -G955FXXU1CRC7_G955FOWA1CRC2_PCT-. But it didn't have the OEM unlock. At one point I remember installing TWRP but something happened to the phone and it wouldn't boot up. So, my act of magic (*coughs*, XDA) I found a way to get it back to official firmware (I think at first it was a Germany's 8.0 firmware*can't find the file name*). Anyways, I want to get the phone to have Wi-Fi calling, VoLTE, etc from T-Mobile and, for what I've interpreted, that comes from the CSC files.

Now, I found a thread that uses TWRP+AROMA to get a list of CSC files on the phone and I can just install the one I want. (I don't know if there's an easier way directly from ODIN but I've not found that compatible TMB CSC file for my phone to get the features working, if any).

In any case I still want my phone rooted (I think I triggered Knox, but the phone updated through the Samsung Updater just fine after installing a PCT 7.0 firmware -G955FXXU1AQCC_G955FOWA1AQCC_PCT-. Clearly I'm out of my depth)

(to the point) The phone doesn't want to install my TWRP file. Says "custom binary(RECOVERY) blocked due to remaining installment balance". Obviously it's Claro's side blocking it, I think?. But I can't get them to unlock it (since it's still "theirs", until I get my case resolved or pay their stupid balance. Long story short, Claro's service is **** and I regret not waiting to get my credit approved my T-Mobile)

So, how do I go about it? I read that its RMM blocked. But my state says normal. The OEM unlock only appears on the 7.0 -G955FXXU1AQCC_G955FOWA1AQCC_PCT- firmware (even then it won't let me install TWRP through ODIN). I honestly don't know. I'll appreciate all the help I can get to reach my goal of getting 100% on T-Mobile's features (mainly VoLTE, if possible-the feature is greyed out so I assume it can be activated). Can't even change the radio band on the thing. I read something about using Nova Launcher and having the widgets activate it through "Enhanced LTE" (I think) but that option doesn't appear on the list. I'd also like to delete all remnants from Claro on the phone, bloatware, booting logo and such. Since it's a 955F, I assume one can make it as if international?

Also, please check my previous post, I just realized I forgot to detail something. I did hit that "your phone has been modified, restart to undo process" and I forgot. Maybe that's the root of it all?

Any questions, please do ask. I'd like to get this moving. :) For now I'll use my Nexus 6 (God I love that phone a lot)

Maybe there's some compensation on this, maybe, if I get it done.

I've included the picture of the error and the info on Download mode, links for files I refer to also at the bottom.

https://www.sammobile.com/firmwares/galaxy-s8-plus/SM-G955F/PCT/download/G955FXXU1CRC7/216223/

https://www.sammobile.com/firmwares/galaxy-s8-plus/SM-G955F/PCT/download/G955FXXU1AQCC/129048/

https://xdaforums.com/showpost.php?p=75360965&postcount=22