NoMethodError (undefined method `synchronize' for nil:NilClass) #4757

assembler opened this Issue Jan 30, 2012 · 6 comments


None yet

5 participants


I've just upgraded to rails 3.2.1 and I get that error whenever i want to do anything with any model. Here is my stack trace ( and here is my gemfile (

I've tried to debug activerecord a bit, and it seems that this line never gets called for any of my models.

I'm using ruby 1.9.2 p290


If I do this during initialization:


then everything works as expected


Hmm, this is strange. Are you able to provide a script to reproduce?. Or a full rails app that produces the problem would be fine. If you want to send me your actual code privately then that's fine also, and I will not disclose it further (obviously). Thanks.


having the same problem. a lot of gems used, though, I'll try to disable them one by one.


Same problem here. Also, I found some other people experiencing this on stack overflow:

vkill commented Jan 31, 2012

try update gem "kaminari" from "0.12.4" to "0.13.0"


@vkill thanks for working that out. looks like kaminari was overwriting the inherited hook, which would explain this. I will also put in a fix to stop this error occurring though.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment