Replicator {error, undef} after update to 3.3.0

[Arnaud - Burotica]

Hello,

I updated my two couchDB servers from v3.2.2 to v3.3.0.
After the update, the replications no longer work
When I want to modify or redo them, I get an {error, undef} message

Best regard

[Ronny Berndt]

Superseeded by apache/couchdb#4344.

[Robert Newson]

can you please grep your couch.log for 'undef' and report the full line with stacktrace if you find it?