Upgrading Redmine from v3 to v5 - problem with plugins

Question

We have an old instance of Redmine running with some old plugins which I wanted to update to their latest versions:

Environment:
  Redmine version                3.4.3.stable
  Ruby version                   2.5.5-p157 (2019-03-15) [x86_64-linux-gnu]
  Rails version                  4.2.8
  Environment                    production
  Database adapter               Mysql2
SCM:
  Git                            2.20.1
  Filesystem                     
Redmine plugins:
  advanced_roadmap_v2            2.4.3
  easy_mindmup                   1.0
  easy_wbs                       1.5
  redmine_agile                  1.4.5
  redmine_checklists             3.1.10
  redmine_contacts               4.1.1
  redmine_contacts_helpdesk      3.0.9
  redmine_custom_reports         0.1.5
  redmine_gc_sync                1.0.0
  redmine_ics_export             3.0.1.dev
  redmine_image_clipboard_paste  3.3.0
  redmine_xlsx_format_issue_exporter 0.1.5

However, I kept running into many issues and errors while trying to upgrade the plugins with the current setup. So I decided to try setting up another Redmine instance and migrate the data there and reinstall the plugins. I downloaded the Redmine 5 stack from Bitnami and managed to import the database and copied over the files. I still get into trouble when attempting to move the plugins over, upon which I can't get into the Redmine frontend anymore. Should I move all the plugins at once from the old Redmine setup or one by one? Thank you.

The frontend is still accessible normally after I migrate the main database. The problems start when I try and get any of the plugins to work. I tried moving all of them at once to the plugins folder, but I get errors on plugin migration. Similar results when I try it with only some of the plugins. Is there a particular order to doing this? What am I doing wrong?

Thank you.

Answer 1

It is recommended that after you move the database and files to redmine5, you then move the plug-in directories to redmine5 one by one. Restart redmine5 every time a plug-in is moved to ensure the compatibility of the plug-ins and exclude plug-ins that cannot be used in redmine5.

Since there are too many differences between your old and new versions of redmine, it is recommended to upgrade them one version at a time.(including your new plugins)

example: redmine3 > redmine4 > redmine5