I administered a written exam built by the awesome exams::exams2nops() function containing multiple choice, single choice and one string question. nops_scan("xx.pdf") and nops_scan("yy.pdf", string = T) worked as a charm and the thereby generated Daten1.txt and Daten2.txt files look as they should.

However, running

ev <- nops_eval(register = "participants.csv",
                solutions = "solutions.rds",
                scans = "nops_scan_20251203064700.zip",
                string_scans = "nops_string_scan_20251203065026.zip")

only recognizes the results of the multiple choice and single choice results correctly. The information of the Daten2.txt seems to be ignored as every answer leads to a score of 0. Furthermore the scan2 column of ev consists of empty strings "".