Dict Replacer (2 Ports) warning: Preprocessing type may not be null!

Dear community,

I really enjoy the ease of use of the many text processing features in Knime. This is a good step forward towards an allround mining tool kit!

Unfortunately, I came across this issue where I get the same warning "Preprocessing type may not be null!" as soon as I have a Dict Replacer (2 ports) node all set up and ready to run. I have a table creator with two columns (and content) as one input and the table containing the documents as the other. All other consecutive nodes are working fine. 

Is this a bug? Or how can I work around this warning?


Hi Robertosh,

the Dictionary Replacer (2 Ports) needs to be applied on a bag of words. Unfortunately this is a bug. You would need to aply the replacer as last preprocessing node. Convert the column containing the documents into a bag or words using the BoW node and than apply the replacer node.

I hope this helps.

Cheers, Kilian