6.2.2. to 6.3.4 upgrade / Distro Upgrade

Hello everyone,

Im using Seafile for some years now on my raspi. I didnt had much time lately due to children etc. but everything worked as intended over the last year.

So im still running Seafile 6.2.2 on Raspbian Jessie on a Pi 3b and want to upgrade to the newest version. Also i think Raspbian Jessie should be updated to stretch for security etc. It also runs a Prosody XMPP Server and a Baikal Calendar server and i remember it took a lot of time to figure out the nginx configs, to get everything working.

I made a whole backup of the working Raspi image and tried first to make the seafile upgrade. The upgrade worked but the change from fastcgi to WSGI didnt work, even i changed the nginx configs as mentioned in the Guide, i got a 502 Error all the time.
I saw this thread where it was told to upgrade python and at least make a dist upgrade Internal Server Error after upgrade from 6.2.5 to 6.3.2
I also tried the python upgrade but this didnt work and i still got the Error, so i decided to upgrade the distro.
After that, it still didnt work and i always got a “internal server Error” on web, client and dav.

So i made a new try, load an SD card with the backup and began the dist upgrade first to see if this would work better.
After the Dist upgrade (with Seafile 6.2.2) seafile still worked except the dav server.

So before i start another dist upgrade and waste time, i would like some advice from you what to do next, and can post the configs, logs etc. from the image i should go on with.