Redmine

I have just installed a fresh v4.1.1 on a new system and tried restoring a mysql database backed up from a v.4.0.5 installation. Unfortunately the restored database gets (almost, but not entirely) inaccessible after the restore. I can login, but only can see very limited sections of it.

I also tried restoring exactly the same db on a new clean v4.0.5 installation with no issues. I spent 2 days on this, and sadly I cannot find a solution.

Here's the steps to reproduce:

1. Installed a fresh v4.1.1 + restored (successfully) a mysql database created in v4.0.5:

gunzip -c /home/xxx/backup/mysql_2020-05-17.gz | sudo mysql --defaults-file=/usr/as/mysql/.my.cnf redmine_default

2. I can successfully login to redmine with the usual 127.0.0.1/redmine. After the login I do see the projects list and the issues list.

3. However, if I click on any project or issue, I get an Error 500 page

4. Inspecting `/usr/share/redmine-4.1.1/log` after clicking on a project shows:

Completed 500 Internal Server Error in 151ms (ActiveRecord: 86.4ms)

ActionView::Template::Error (undefined method `description' for #<Tracker:0x00005613c65be020>):
        65:       <% @trackers.each do |tracker| >
        66:         &lt;tr&gt;
        67:           &lt;td class="name"&gt;
        68:             <= link_to tracker.name, project_issues_path(@project, :set_filter => 1, :tracker_id => tracker.id), :title => tracker.description >
        69:           &lt;/td&gt;
        70:           &lt;td&gt;
        71:             <= link_to @open_issues_by_tracker[tracker].to_i, project_issues_path(@project, :set_filter => 1, :tracker_id => tracker.id) %>

app/views/projects/show.html.erb:68:in `block in app_views_projects_show_html_erb_3010486713022863027_70353520498380'
    app/views/projects/show.html.erb:65:in `_app_views_projects_show_html_erb__3010486713022863027_70353520498380'
    lib/redmine/sudo_mode.rb:65:in `sudo_mode'

I'm running:
- Linux Mint 19.3
- mysql Ver 14.14 Distrib 5.7.28, for Linux (x86_64) using EditLine wrapper
- ruby ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux-gnu]
- rails 5.2.4.2
- no plugins installed