The job database version (for recreate case) is unimportant, but (quoting from the directions)
Since both the server database and the local database was updated, you need to downgrade both.
Not downgrading the server database means the server will find the wrong version, so not start. Messages on this exist, but are hard to find. Here’s the start of what Duplicati-crashlog.txt says:
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Exception: A serious error occurred in Duplicati: System.Exception: Failed to create, open or upgrade the database.
Error message:
The database has version 8 but the largest supported version is 6.
This is likely caused by upgrading to a newer version and then downgrading.
The old version of 6 is what the directions say to go to. The new value of 8 is in release note as:
Old versions of Duplicati are unable to read database formats that did not exist at their time, so downgrading Duplicati means changing both the format and the version number back to the old.
EDIT:
I don’t know if that answered your question. I view downgrading as probably difficult for a typical person. Technical abilities vary. There’s no custom Duplicati downgrading tool, only a procedure.