@UlrikeFischer, last lines are:2017-10-06 13:06:55,481+0200 INFO FileCopyPage -
2017-10-06 13:06:55,485+0200 INFO FileCopyPage - Sorry, but "MiKTeX Configuration Utility" did not succeed.
2017-10-06 13:06:55,485+0200 INFO FileCopyPage -
2017-10-06 13:06:55,489+0200 INFO FileCopyPage - The log file hopefully contains the information to get MiKTeX going again:
2017-10-06 13:06:55,489+0200 INFO FileCopyPage -
2017-10-06 13:06:55,494+0200 INFO FileCopyPage - C:/Users/Zarko/AppData/Local/MiKTeX/2.9/miktex/log/initexmf.log