As said, I recall having no issues using the procedure from https://forum.xda-developers.com/sho...45&postcount=2
How to dirty flash an official weekly over an unofficial build (and vice versa)?
When trying to update an unofficial build to an official weekly build, I get an error message in TWRP saying
"Can't install this package on top of incompatible data. Please try another package or run a factory reset". How do I fix that?
At the start of an installation the installer checks the build keys. They differ between unoffical and official builds, and the installer refuses to overwrite builds with different keys. To fix this you have to install the official keys before trying to install the official build:
- Run this script called lineage-migration-signed.zip in TWRP.
- Then install the official ROM zip.
There may be reason to dirty flash an unofficial build over an official build, for instance, if you're developing or testing new stuff. The problem is the same, just in the other direction: You have to install the unofficial build keys:
- Run this script called lineage-migration-unsigned.zip in TWRP.
- Then install the unofficial ROM zip.
See also my post from August in this thread.
Best of success!