Answer by bcarlsen for Shiny DT datatable Make only certain columns editable by the user

According to the documentation for DT::datatable(), the editable argument should be structured differently:

This argument can also be a list of the form list(target = TARGET,disable = list(columns = INDICES)), where TARGET can be cell, row,column, or all, and INDICES is an integer vector of column indices.

Try editable = list(target = "column", disable = list(columns = c(1,2))