no marshal_dump is defined for class

11175 (-- --) August 21, 2009, 5:16pm 1

Hi all, Does anyone knows what this error message means?

Topic		Replies	Views
no marshal_dump is defined for class StringIO rubyonrails-talk	0	219	March 18, 2008
why Marshal.dump a relation obejct would faile rubyonrails-talk	1	931	September 18, 2019
/!\ FAILSAFE /!\ error with Rails 2.3.4 rubyonrails-talk	2	181	February 2, 2010
no _dump_data is defined for class Mysql2::Result rubyonrails-talk	4	166	January 29, 2014
Type Error , can't dup NilCLASS rubyonrails-talk	0	146	May 10, 2010