# Mongrel fails to start after installation of plugin prawnto **URL:** \ **Category:** Rails\ **Created:** [January 10, 2010, 12:23pm UTC](https://www.ruby-forum.com/t/mongrel-fails-to-start-after-installation-of-plugin-prawnto/181349 "2010-01-10T12:23:23Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![trapper](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/2acd7d/32.png) [@trapper](https://www.ruby-forum.com/u/trapper)\ **Post date:** [January 10, 2010, 12:23pm UTC](https://www.ruby-forum.com/t/mongrel-fails-to-start-after-installation-of-plugin-prawnto/181349/1 "2010-01-10T12:23:23Z")
After I installed prawnto in my project, Mongrel fails to start with these backtrace lines: /home/inet/Aptana RadRails Workspace/wvz/vendor/rails/activesupport/lib/active\_support/dependencies.rb:275:in `load_missing_constant': uninitialized constant ActiveSupport::Memoizable (NameError) from /home/inet/Aptana RadRails Workspace/wvz/vendor/rails/activesupport/lib/active_support/dependencies.rb:467:in`const\_missing’ from /home/inet/Aptana RadRails Workspace/wvz/vendor/plugins/prawnto/lib/prawnto/template\_handler/compile\_support.rb:5 Any idea how to fix this? ---
**Author:** ![trapper](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/2acd7d/32.png) [@trapper](https://www.ruby-forum.com/u/trapper)\ **Post date:** [January 10, 2010, 3:07pm UTC](https://www.ruby-forum.com/t/mongrel-fails-to-start-after-installation-of-plugin-prawnto/181349/2 "2010-01-10T15:07:07Z")
On 10 Jan, 11:23, Fritz T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > After I installed prawnto in my project, Mongrel fails to start with > these backtrace lines: Sounds like your app is using a version of rails that is too old fred ---
**Author:** ![trapper](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/2acd7d/32.png) [@trapper](https://www.ruby-forum.com/u/trapper)\ **Post date:** [January 10, 2010, 3:45pm UTC](https://www.ruby-forum.com/t/mongrel-fails-to-start-after-installation-of-plugin-prawnto/181349/3 "2010-01-10T15:45:28Z")
Frederick C. wrote: > On 10 Jan, 11:23, Fritz T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > After I installed prawnto in my project, Mongrel fails to start with > > these backtrace lines: > > Sounds like your app is using a version of rails that is too old That’s what I guessed and for that completly uninstalled rails and gem from my system and reinstalled gem1.8 + rails 2.3.5 But it did not change anything. Running ‘script/server’ -u’ from my project still invokes /home/inet/.gem/ruby/1.8/gems/activesupport-2.1.0/… stuff, while 2.3.5 is also available there. How to update the project? (Running rails:update didn’t help.) ---
**Author:** ![trapper](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/2acd7d/32.png) [@trapper](https://www.ruby-forum.com/u/trapper)\ **Post date:** [January 10, 2010, 5:40pm UTC](https://www.ruby-forum.com/t/mongrel-fails-to-start-after-installation-of-plugin-prawnto/181349/4 "2010-01-10T17:40:28Z")
On 10 Jan, 14:45, Fritz T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Frederick C. wrote: > How to update the project? (Running rails:update didn’t help.) the version to use is set in environment.rb (unless you have frozen rails into vendor) fred ---
**Author:** ![trapper](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/2acd7d/32.png) [@trapper](https://www.ruby-forum.com/u/trapper)\ **Post date:** [January 10, 2010, 6:19pm UTC](https://www.ruby-forum.com/t/mongrel-fails-to-start-after-installation-of-plugin-prawnto/181349/5 "2010-01-10T18:19:34Z")
Frederick C. wrote: > the version to use is set in environment.rb (unless you have frozen > rails into vendor) Thanks, now the debugger is starting up, but the bad news is, that I still get the same message, than with the former version: uninitialized constant ActiveSupport::Memoizable (NameError) How to get rid of this plugin? ---
**Author:** ![trapper](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/2acd7d/32.png) [@trapper](https://www.ruby-forum.com/u/trapper)\ **Post date:** [January 10, 2010, 8:22pm UTC](https://www.ruby-forum.com/t/mongrel-fails-to-start-after-installation-of-plugin-prawnto/181349/6 "2010-01-10T20:22:13Z")
Fritz T. wrote: > uninitialized constant ActiveSupport::Memoizable (NameError) This was nonsense, sorry. mysql was missing. After running apt-get install libmysqlclient15-dev gem install mysql My app now runs again. Thanks for your help.