Defect #30513

Unable to load the EventMachine C extension; windows

Added by James H over 1 year ago. Updated over 1 year ago.

Status:ClosedStart date:
Priority:NormalDue date:
Assignee:-% Done:


Category:Ruby support
Target version:-
Resolution:Invalid Affected version:4.0.1


Upgrading from Redmine 3.3.x to 4.0.1

on cmd:

rake generate_secret_token

I get this error:

Unable to load the EventMachine C extension; To use the pure-ruby reactor, require 'em/pure_ruby'
rake aborted!
LoadError: cannot load such file -- 2.5/rubyeventmachine
X:/Redmine/config/application.rb:5:in '<top <required>>'
X:/Redmine/Rakefile:5:in '<top <required>>'

Resolved by adding the following line:

require 'em/pure_ruby'

at the top of


#1 Updated by James H over 1 year ago

I am personally using Ruby 2.5.3
but I have seen this resolution for 2.4.x and I believe 2.6.x as well.

#2 Updated by James H over 1 year ago

After the resolution above,
running rake generate_secret_token gives a lot of the same warning:

X:/Redmine/app/models/wiki_content_version.rb:xxx: warning: encountered \r in middle of line, treated as a mere space

Then when I start up a server (I usually use Thin client) I got a

no implicit conversion of nil into String <TypeError>

from the thin files.

These could all be unrelated, not sure at this time.

#3 Updated by James H over 1 year ago

uninstall eventmachine x64-mingw32

gem install eventmachine --platform ruby

#4 Updated by Holger Just over 1 year ago

  • Status changed from New to Closed
  • Resolution set to Invalid

Thank you for your report.

Unfortunately, Redmine itself doesn't use eventmachine anywhere. If something requires eventmachine with your installation, this requirement is thus likely stemming from some customizations of your setup (e.g. because you use an app server like thin or some custom plugin). In that case, any issues caused by those components should be reported to the authors of the respective projects.

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