# ri > ActiveSupport::SafeBuffer::SafeConcatError

## [ActiveSupport::SafeBuffer::SafeConcatError](https://www.chedong.com/phpMan.php/perldoc/ActiveSupport%3A%3ASafeBuffer%3A%3ASafeConcatError/markdown) < StandardError

(from /home/chedong/.local/share/rdoc)
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Raised when [ActiveSupport::SafeBuffer](https://www.chedong.com/phpMan.php/perldoc/ActiveSupport%3A%3ASafeBuffer/markdown)#safe_concat is called on unsafe
buffers.
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## Class methods:

  new