Question Downgrade LE2115 from 12 to 11 - confused.

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aaronbaird1

Member
Dec 25, 2008
16
1
Hello all,

My phone came with ColorOS OOS 12 and I hate it. As soon as I rooted it it started crashing daily, I even reflashed a fresh oos12 image using the local update tool and only granted superuser to one app (solid explorer so I could access user files) and it still crashes. Not to mention all the apps i want to use don't work on android 12 (call recorder, busy box) and no custom recovery.

I've been reading through the forum and I found a downgrade package that looks like its hosted by oneplus: https://oxygenos.oneplus.net/OnePlu...all_2107082125_downgrade_059624cc7298428b.zip

I just wanted to make sure I am doing this correctly...
  1. Do I use the OP Local Update app to flash?
  2. Will I be able to flash TWRP for android 11 afterwards?
  3. Will i need to relock the bootloader?
  4. Should i re-root using the magisk slot b method or wait until its flashed and use TWRP?
  5. Will it try to OTA back to android 12? If so, what's the best method to get on the latest version of android 11?

Thanks for the help.
 
Last edited:

EtherealRemnant

Senior Member
Sep 15, 2007
3,563
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Denver, CO
I am running COS C.62 on my OP9 with root and having no issues. Did you make sure to do all the things in this guide?


Anyway, yes, use the local upgrade APK, put the downgrade file in the root of storage, run it. Reboot. Factory reset and wipe data to clear out any leftover crap (don't restore a backup - if you want to use Clone Phone you can do that but only restore app APKs and messages). When it reboots it should offer the latest OOS11 OTA first. If not, just download it and place it in the root and use the local upgrade function in the settings menu of the OOS11 system updater.

There is no need re-lock the bootloader and if you do, you risk a brick that has to be recovered with MSM Tool.

Root by following the guide I linked. I just went through this yesterday after flashing COS broke mobile data. I have Magisk 24.3 working with denylist, Widevine L1, and SafetyNet passes so I have Google Pay.
 

aaronbaird1

Member
Dec 25, 2008
16
1
I am running COS C.62 on my OP9 with root and having no issues. Did you make sure to do all the things in this guide?


Anyway, yes, use the local upgrade APK, put the downgrade file in the root of storage, run it. Reboot. Factory reset and wipe data to clear out any leftover crap (don't restore a backup - if you want to use Clone Phone you can do that but only restore app APKs and messages). When it reboots it should offer the latest OOS11 OTA first. If not, just download it and place it in the root and use the local upgrade function in the settings menu of the OOS11 system updater.

There is no need re-lock the bootloader and if you do, you risk a brick that has to be recovered with MSM Tool.

Root by following the guide I linked. I just went through this yesterday after flashing COS broke mobile data. I have Magisk 24.3 working with denylist, Widevine L1, and SafetyNet passes so I have Google Pay.
Thank you, ill give it a try.

First i used the payload.bin method and it was crashing, then i reflashed the latest OTA using the local update tool and used the magisk slot b method. still crashing.

It might have less to do with the root and more with me using root to disable certain apps (youtube, chrome, OP community, google news/podcast/tv) i dont want them on my phone but they might be too tightly integrated. If its still crashing on android 11 ill re-enable them and see if that helps.
 

EtherealRemnant

Senior Member
Sep 15, 2007
3,563
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Denver, CO
Thank you, ill give it a try.

First i used the payload.bin method and it was crashing, then i reflashed the latest OTA using the local update tool and used the magisk slot b method. still crashing.

It might have less to do with the root and more with me using root to disable certain apps (youtube, chrome, OP community, google news/podcast/tv) i dont want them on my phone but they might be too tightly integrated. If its still crashing on android 11 ill re-enable them and see if that helps.
Okay you're on OOS, not COS. COS doesn't have Google apps by default (but has plenty more bloatware, I just don't use it).

It's certainly possible that disabling Google apps is your problem. If you don't want Google apps, you're better off with a custom ROM that doesn't have them. CalyxOS has a beta for OnePlus 9 and it's totally de-Googled. There's also Lineage.
 

aaronbaird1

Member
Dec 25, 2008
16
1
Okay you're on OOS, not COS. COS doesn't have Google apps by default (but has plenty more bloatware, I just don't use it).

It's certainly possible that disabling Google apps is your problem. If you don't want Google apps, you're better off with a custom ROM that doesn't have them. CalyxOS has a beta for OnePlus 9 and it's totally de-Googled. There's also Lineage.
ahhhh. i didnt realize there was a difference. I thought OP was just calling their android 12 build ColorOS.

Either way, for custom roms i would have to go back to 11 to flash TWRP right? or can you flash custom roms using fastboot?
 

EtherealRemnant

Senior Member
Sep 15, 2007
3,563
1,055
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Denver, CO
ahhhh. i didnt realize there was a difference. I thought OP was just calling their android 12 build ColorOS.

Either way, for custom roms i would have to go back to 11 to flash TWRP right? or can you flash custom roms using fastboot?
You would need to back to 11 because OnePlus hasn't released working sources for 12. Just use the downgrade package, factory reset, then upgrade to 11.2.10.10 and you'll be good to go for custom ROMs. TWRP isn't used for flashing them, they all generally post their own recovery. StagOS was the best one I used (plus the dev is really responsive when there are issues) and people seem to really be enjoying Nameless but that came out after I went back to stock so I haven't tried it yet.

Before you mess with custom ROMs, make sure that you download the global MSM Tool and make sure you can connect it. Honestly since you have to go back anyway, might as well download and use the MSM Tool to get the device back to 11 anyway.


Easiest way to get it into EDL is adb reboot edl but if you want to practice the key combination in case you can't get into the OS, I found if you open the MSM, check use lite firehose, and click Start before you connect the phone, it has less connection errors because it's waiting for the phone so as soon as you connect the cable, it pops up.