Zammad crashed after 3.6 update?

Technical assistance
7

Hm… it looks like there is no easy way for a downgrad…
I just ran into a new problem with IMAP fetching:

I, [2020-11-17T10:25:08.926058 #31786-47023157155680] INFO – : - message 1/1
I, [2020-11-17T10:25:09.507574 #31786-47023157155680] INFO – : Process email with msgid ‘h6Fxp7mVUg1K8uK7kAsKcGXl5OZmlJg6Q7cEmxAeU@ovm2336’
E, [2020-11-17T10:25:09.519129 #31786-47023157155680] ERROR – : Can’t process email, you will find it for bug reporting under /opt/zammad/tmp/unprocessable_mail/6648b5c03d29e95622d708f445d8278f.eml, please create an issue at Issues · zammad/zammad · GitHub
E, [2020-11-17T10:25:09.519192 #31786-47023157155680] ERROR – : uninitialized constant Channel::Filter::ImportArchive (NameError)
/opt/zammad/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.4.4/lib/active_support/inflector/methods.rb:285:in const_get' /opt/zammad/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.4.4/lib/active_support/inflector/methods.rb:285:in block in constantize’
/opt/zammad/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.4.4/lib/active_support/inflector/methods.rb:281:in each' /opt/zammad/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.4.4/lib/active_support/inflector/methods.rb:281:in inject’
/opt/zammad/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.4.4/lib/active_support/inflector/methods.rb:281:in constantize' /opt/zammad/vendor/bundle/ruby/2.6.0/gems/activesupport-5.2.4.4/lib/active_support/core_ext/string/inflections.rb:68:in constantize’
/opt/zammad/app/models/channel/email_parser.rb:147:in block in _process' /opt/zammad/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.4.4/lib/active_record/relation/delegation.rb:71:in each’
/opt/zammad/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.4.4/lib/active_record/relation/delegation.rb:71:in each' /opt/zammad/app/models/channel/email_parser.rb:146:in _process’
/opt/zammad/app/models/channel/email_parser.rb:118:in block in process' /opt/zammad/vendor/ruby-2.6.6/lib/ruby/2.6.0/timeout.rb:93:in block in timeout’
/opt/zammad/vendor/ruby-2.6.6/lib/ruby/2.6.0/timeout.rb:33:in block in catch' /opt/zammad/vendor/ruby-2.6.6/lib/ruby/2.6.0/timeout.rb:33:in catch’
/opt/zammad/vendor/ruby-2.6.6/lib/ruby/2.6.0/timeout.rb:33:in catch' /opt/zammad/vendor/ruby-2.6.6/lib/ruby/2.6.0/timeout.rb:108:in timeout’
/opt/zammad/app/models/channel/email_parser.rb:117:in process' /opt/zammad/app/models/channel/driver/imap.rb:294:in block in fetch’
/opt/zammad/app/models/channel/driver/imap.rb:229:in each' /opt/zammad/app/models/channel/driver/imap.rb:229:in fetch’
/opt/zammad/app/models/channel.rb:57:in fetch' /opt/zammad/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.4.4/lib/active_record/relation/delegation.rb:71:in each’
/opt/zammad/vendor/bundle/ruby/2.6.0/gems/activerecord-5.2.4.4/lib/active_record/relation/delegation.rb:71:in each' /opt/zammad/app/models/channel.rb:32:in fetch’
(eval):1:in _start_job' /opt/zammad/app/models/scheduler.rb:287:in eval’
/opt/zammad/app/models/scheduler.rb:287:in _start_job' /opt/zammad/app/models/scheduler.rb:239:in block (2 levels) in start_job’
/opt/zammad/app/models/scheduler.rb:237:in loop' /opt/zammad/app/models/scheduler.rb:237:in block in start_job’
/opt/zammad/vendor/bundle/ruby/2.6.0/gems/logging-2.2.2/lib/logging/diagnostic_context.rb:474:in `block in create_with_logging_context’

I looked up the error “uninitialized constant Channel::Filter::ImportArchive (NameError)” and found this topic:

@MrGeneration could you explain briefly how to undo a migration and redo it afterwards?