Samsung S7 SM-G930F update to /e/Oreo failed

Hello Community,
can anybody help me with the following matter.
I use the a/m S7 herolte which I bought from e-foundation. Additionally I installed Magisk and AFWall+. It was running perfectly.
Now I tried to update from /e/Nougat to /e/Oreo using the steps as described here:


Something failed. The device is still starting, but some features are not working anymore. This is for instance the WLAN. After switching it on, it goes off again after a few seconds.
All entries of my calender are missing (of course I have a backup).
Has anybody an idea what can I do in order to restore the old status?
I would like to avoid to built it up completely again.

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