# ActiveRecord SerializationTypeMismatch MySQL SQLite

**URL:** <https://www.ruby-forum.com/t/activerecord-serializationtypemismatch-mysql-sqlite/168248>\
**Category:** Rails\
**Created:** [May 18, 2009, 6:15pm UTC](https://www.ruby-forum.com/t/activerecord-serializationtypemismatch-mysql-sqlite/168248 "2009-05-18T18:15:37Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![juan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a698b9/32.png) [@juan](https://www.ruby-forum.com/u/juan)\
**Post date:** [May 18, 2009, 6:15pm UTC](https://www.ruby-forum.com/t/activerecord-serializationtypemismatch-mysql-sqlite/168248/1 "2009-05-18T18:15:37Z")

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I was having this error in Development but not in Test:

ActiveRecord::SerializationTypeMismatch: cambiable\_attributes was  
supposed to be a Hash, but was a String

Which was the problem?  
I was using MySQL in Development and SQLite3 in Test. Field  
‘cambiable\_attributes’ was type String in the DB schema and had to be  
type Text.  
I changed the data type to Text and it worked well in both environments.