CookierStore::CookieOverflow

/!\ FAILSAFE /!\  Sun Mar 22 23:51:44 -0700 2009
  Status: 500 Internal Server Error
  ActionController::Session::CookieStore::CookieOverflow

This error is typically due to the user trying to store > 4K of data in the session.

Another source of error is if you try to store $! in flash[:error]

begin
  ....
rescue 
  flash[:error] = $!
end

This tries to store the ruby exception object in the flash (which in turn is stored in the cookie) and you will start getting the cookie overflow errors.

The solution is simple

begin
  ....
rescue 
  flash[:error] = $!.to_s
end

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