[Magisk] iankelly2001:
Magisk v19.0 beta Download Bootloop on Samsung Galaxy S5 SM-G900F

Sorry kotuamoalt, but I missed this reply before. No, nothing is encrypted. And no, SuperSU has never been installed on this phone since installing a custom ROM.

HOWEVER, although I never managed to successfully install Magisk 19.0 beta on my phone, I have at last had some success installing the latest available Magisk Canary build v19.0-3eae9494 (19001). I will make a separate post describing the steps I used, for the benefit of others who have been struggling with the Download bootlooping problem on their Galaxy S5.

---------- Post added at 08:51 PM ---------- Previous post was at 08:17 PM ----------

For those of you having problems with installing Magisk v19.0 beta causing a download mode bootloop, although I have still not managed to get the beta version installed, I have had success today with installing the subsequent Canary build v19.0-3eae9494 (19001) and subsequently installing the Magisk Manager APK v7.1.1-5b30c774 (204). I had Magisk v18.1 previously installed on my phone, which is running Resurrection Remix v7.01 (KTLE) for Pie 9.0.

The steps I followed:

(1) I did a full TWRP backup as usual, ready to restore if I got into another download bootloop.

(2) I downloaded the latest Magisk Uninstaller, Magisk Canary version and Magisk Manager from the links in the Magisk Canary XDA thread

(3) I restarted my phone into TWRP recovery, and installed the Uninstaller zip and rebooted

(4) The phone immediately went into the download bootloop (BUT DON'T PANIC, the following steps got me out of it and if they don't, restoring the full TWRP backup should get you back to a working system)

(5) I forced the phone into TWRP recovery by holding down VOL UP + HOME + POWER buttons together for ten seconds or so

(6) Without wiping anything, I installed the zip for custom ROM and Kernel in one go

(7) I let the phone reboot into system, which got me out of the download bootloop, and the system loaded, with all settings and data intact, but with Magisk v18.1 successfully uninstalled

(8) Restarted phone into TWRP Recovery

(9) Installed the Magisk Canary zip (the file name is just magisk-release.zip) and rebooted (don't wipe anything)

(10) The phone miraculously rebooted into system without going into a download bootloop

(11) Installed app-release.apk from the working system (Magisk Manager)

(12) Opened Magisk Manager and checked Magisk was now installed

I hope this helps anyone who wants to try the Version 19 flavour of Magisk, albeit perhaps taking risks of more things being broken in an experimental version instead of having a beta version on their S5. Whether it will finally allow me to use Google Pay without problems remains to be seen!

FOOTNOTE: I experienced another Download Bootloop after I restarted after installing some Magisk Modules. I had reinstall the Canary Magisk zip again after forcing the phone back into TWRP Recovery to get it back on track. Oh my! I've rebooted a few more times just to make sure the Download Bootloop doesn't reoccur. It's certainly a very fragile process at the moment on the S5.

FURTHER FOOTNOTE 2 April 2019: As a bonus, Google Pay is working for the first time ever with the above Magisk v19 Canary build. Just managed to make an in-store contactless payment. It never worked for me using Magisk 18.1.

FURTHER UPDATE: Despite the initial success, on subsequent reboots of the phone - back into download bootloop, despite several previous successful boots into system with the Magisk Canary build fully working. I can't make head or tail of this.