I have now looked at the different answers in this thread and I am not sure: Can I upgrade my Fairphone 3 with LineageOS 17.1 and locked bootloader to LineageOS 18.1 without losing my personal data and apps?
Apart from that, will LineageOS 17.1 still get security updates?
It seems like you wonāt have any problem if you donāt use Magisk. However, if you do use Magisk, youāre likely to have problems.
You shouldnāt lose your data and apps if you properly follow the official upgrade guide : Upgrade LineageOS on FP3 | LineageOS Wiki. Nevertheless, I advise you to backup important data to your computer before upgrading.
Lineageos 17.1 wonāt receive updates anymore now that 18.1 is official.
Yes, you can, without data loss. I did that myself following exactly the upgrade instructions.
With a (re-)locked bootloader, it is not that easy to make a full back-up though, since you canāt boot to TWRP.
Thank you for your advise @Adrian_D and @clemsys . So I will make a backup and try it in the next days.
So I will just follow the LineageOS FP3 Wiki page and then do fastboot oem lock and Iāll be golden?
Hello,
I would like to update my LineageOS 17.1 to 18.1 like it was described here. I read a lot about problems and stopping while starting the system. I would like to know which way is the best in my caseā¦ I use magisk for rooting and I donāt use Google. Does clean flash always work?
Thanks in advance for your help!
To upgrade you can follow the LOS Wiki-Page. It did work for me without data loss.
But if you lock your bootloader this will wipe your device.
Last week I could fix my signal problem.
Since monday Iāve upgraded OTA. With the new built bluetooth works again.
Sometimes trouble with brightness and sometimes wifi-issues. Means Iām connected but no data is transferred. After few seconds itās working again. Iām not sure whether the wifi issue is a hardware or LOS18.1 problem. I will try to check it.
Anyway thank you very much for your time to support the LOS FP3 built in your free time. I really appreciate this!
Another one: The charging sound in developer options does not change, whatever sound is set there, the only sound i hear is āChargingStartedā.
Wipe as in āwipe my data partitionā or wipe as in āthe device is completely blankā?
Its LOS18.1 Problem. I downgraded my device back to 17.1 and: WiFi is fine
@BiggusDiggus
wipe data means, normally, just your Apps incl data/settings
Btw:
āFairphone 3 and 3+, the company says itās planning an Android 11 update in the second half of this year. Fairphone says Qualcomm is planning to kill support for the Snapdragon 632 chip that underpins these phones in July 2021. Fairphone wants to deliver āat least one more major Android updateā after Android 11, but that will mean doing another update without Qualcommās support.ā
I have now tried to upgrade my Fairphone 3 to LineageOS, but I fail at the point where i try to sideload the file. Down below you see a screenshot of the error message:
What did I do wrong?
Can somebody help me?
The link to the files you want to sideload is incorrect: remove the ā/path/to/ā
so just adb sideload C:\JH...signed.zip?
Yes that will do, I think.
Thank you, now it works.
Success! I also upgradet to LineageOS 18.1 witout any data loss!
Thanks for the hard work! Upgrade from LOS 17.1 to 18.1 with OpenGapps-nano was painless 
FYI: the LOS4microG 18.1 build for FP3 is available now
I just switched to that build from LOS 18.1. It seems to work so far. I dirty-flashed it with recovery (adb sideload)
But here too I have problems with Magisk: after I flashed the zip file with Recovery, the system still crashes when bootingā¦ 
At least after reflashing LOS4microG the OS is working so far. Without Magisk/root, but at least with microG 
A huge thanks to @dk1978 @TeamB58 and all others who made this possible 
Just installed LOS 18.1 MicroG, easy peasy! Happy to be back on a Lineage build, but look forward to Magisk working.
Big thanks to all involved
