When Error query is selected, you can search on the error code or the correction code on the main panel by selecting your choice in the drop down box. When you click make concordance, the text marked as having that error (or correction) code is selected as the KWIC (middle column of the concordance). The error codes are listed at the error codes link. You can use a wild card search e.g. “.*” or e.g. “#M.*“. You can also search on the actual text marked with the error or correction codes using the Incorrect word/s or Corrected word/s boxes respectively.
For help on Expert options see the Concordance Query page though note that the Query type option is not available for Error queries.